Highly Simplified Reddish Orange Phosphorescent Organic Light

Subscriber access provided by Olson Library | Northern Michigan University

Article

Highly Simplified Reddish Orange Phosphorescent Organic LightEmitting Diodes Incorporating a Novel Carrier- and ExcitonConfining Spiro-exciplex-forming Host for Reduced Efficiency Roll-off Ting Xu, Ye-Xin Zhang, Bo Wang, Chen-Chao Huang, Imran Murtaza, Hong Meng, and Liang-Sheng Liao ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.6b13077 • Publication Date (Web): 30 Dec 2016 Downloaded from http://pubs.acs.org on January 2, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

ACS Applied Materials & Interfaces is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Materials & Interfaces

Highly Simplified Reddish Orange Phosphorescent Organic Light-emitting Diodes Incorporating a Novel Carrier- and Exciton-confining Spiro-exciplex-forming Host for Reduced Efficiency Roll-off 7LQJ ;XD >1 1 GL S WRO\O DPLQR@SKHQ\O@ F\FORKH[DQH

7$3& ZKLFK VLJQLILFDQW GHFUHDVH LQ WKH GULYH YROWDJH ZDV H[KLELWHG H[WUD OD\HU

QHHGHG WR EDODQFH FDUULHUV WUDQVSRUW

+RZHYHU

DQG ORZHU WKH FKDUJH WUDQVSRUW

EDUULHU ODUJHO\ LQFUHDVHV WKH PDQXIDFWXULQJ FRVWLQJ DQG DOVR EULQJV H[WUD KHWHUR MXQFWLRQV LQWR WKH 2/('V ZKLFK XVXDOO\ DUH GHWULPHQWDO WR LWV VWDELOLW\ 6R WKHUH LV

ACS Paragon Plus Environment

Page 5 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


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

+RZHYHU VHOGRP UHVHDUFKHUV

SDLG DWWHQWLRQ WR DSSO\ VSLUR EDVHG RUJDQLF PDWHULDOV DV KRVW DQG +7/ VLPXOWDQHRXVO\ DV D VDOO\ SRUW WR VLPSOLI\ GHYLFH VWUXFWXUH DQG IDEULFDWLRQ SURFHVV RI 3K2/('V ZLWKRXW VDFULILFLQJ GHYLFH SHUIRUPDQFH 2Q WKH RWKHU KDQG &( UROO RII LV RQH RI PRVW XVXDO ZHDNQHVV RI 3K2/('V ZKLFK PD\ OLPLW WKHLU LPSOHPHQWDWLRQ DW KLJK EULJKWQHVV LQ OLJKWLQJ DSSOLFDWLRQV WULSOHW DQQLKLODWLRQ

77$

WULSOHW SRODURQ TXHQFKLQJ

TXHQFKLQJ DUH SRVVLEOH TXHQFKLQJ SURFHVVHV LQ 2/('V

734

7ULSOHW

DQG ILHOG LQGXFHG

%DOGR HW DO

UHSRUWHG WKDW

77$ LV WKH SULPDU\ UHDVRQ FDXVHG WKH &( UROO RII RI 2/('V ZKLOH 5HLQHNH HW DO

KROG

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



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 30

VDFULILFLQJ GHYLFH SHUIRUPDQFH ZKLOH UHGXFLQJ &( UROO RII E\ FDUULHU DQG H[FLWRQ FRQILQLQJ VSLUR H[FLSOH[ IRUPLQJ KRVW 7KH IROORZLQJ UXOHV DUH UHTXLUHG IRU D KLJKO\ VLPSOLILHG H[FLSOH[ IRUPLQJ KRVW IRU QRYHO 3K2/('V

$ VXLWDEOH ORZHVW XQRFFXSLHG

PROHFXODU RUELWDO /802 OHYHO RI +7/ FROORFDWLQJ ZRUN IXQFWLRQ :) RI ,72 DQRGH LQ FRQYHQWLRQDO 2/('V IRU WKH VDNH RI DYRLGLQJ UHTXLUHPHQWV IRU PXOWLSOH WUDQVSRUW OD\HUV

7 OHYHO RI GRQRU DQG DFFHSWHU RI DQ H[FLSOH[ IRUPLQJ KRVW VKRXOG H[FHHG

7 OHYHO RI D SKRVSKRUHVFHQW JXHVW WR FRQILQH OLPLWHG UDQJH UHFRPELQDWLRQ ]RQH DQG UHDOL]H WKH HQHUJ\ WUDQVGXFWLRQ IURP WKH H[FLSOH[ IRUPLQJ KRVW WR D UHG JXHVW DQG 'HHSHU +202 KLJKHVW RFFXSLHG PROHFXODU RUELWDO RI (7/ HOHFWURQ WUDQVSRUW OD\HU DQG KLJKHU /802 RI VSLUR VHULHV PDWHULDOV FRQILQLQJ H[FLWRQ UHFRPELQDWLRQ ]RQH WR DYRLG TXHQFKLQJ GXULQJ FKDUJH WUDQVSRUW +HUHLQ ZH UHSRUW D QRYHO H[FLSOH[ IRUPLQJ KRVW DUFKLWHFWXUH E\ FRPELQLQJ 1 1 WULSKHQ\O

+ VSLUR>DFULGLQH

IOXRUHQ@

DPLQH 6$)'3$ ZLWK

GLSKHQ\O

SKHQDQWKUROLQH %SKHQ WR H[SORUH FRPPRQ HOHFWURQ WUDQVSRUW PDWHULDO DQG IXUWKHU DSSO\ LQWR D KLJKO\ VLPSOLILHG RUDQJH UHG SKRVSKRUHVFHQFH 2/(' VWUXFWXUH $ VXLWDEOH /802 RI 6$)'3$ PDWFKHV WKH :) RI WKH ,72 DQRGH RI FRQYHQWLRQDO 2/('V WR DYRLG WKH UHTXLUHPHQW IRU PXOWLSOH WUDQVSRUW OD\HUV 0RUHRYHU WKH 7 OHYHO RI WKH H[FLSOH[ LV KLJKHU

WKDQ

WULYDOHQW

LULGLXP

K@TXLQR[DOLQH DFHW\ODFHWRQDWH LULGLXP ,,,

FRPSOH[ ,U 0'4

WUDQVIHUV WR D UHGGLVK RUDQJH GRSDQW RI ,U 0'4

ELV DFDF

PHWK\OGLEHQ]R>I H9 VR WKDW HQHUJ\

DFDF )XUWKHUPRUH WKH GHVLJQHG

2/('V ZLWK UHGGLVK RUDQJH HPLVVLRQ DQG XVLQJ 6$)'3$ %SKHQ

Z Z PL[HG

KRVW DUFKLWHFWXUH DQQLKLODWLQJ DGGLWLRQDO KROH WUDQVSRUW PDWHULDO VKRZ VLPSOHU GHYLFH


Page 7 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


VWUXFWXUH ZLWK GHHSHU +202 RI %SKHQ DQG KLJKHU /802 RI 6$)'3$ FRQILQLQJ H[FLWRQ UHFRPELQDWLRQ ]RQH WR DYRLG TXHQFKLQJ GXULQJ WKH SURFHVV RI WUDQVSRUWDWLRQ /RZHU ZRUNLQJ YROWDJH EHWWHU HIILFLHQF\ DQG VWDELOLW\ DUH DFKLHYHG FRPSDUHG ZLWK WKH UHIHUHQFH GHYLFH DSSO\LQJ

ELV > >1 1 GL

WRO\O DPLQR@ SKHQ\O@ F\FORKH[DQH

7$3& DV WKH KROH WUDQVSRUW OD\HU ZLWKRXW WKH FR KRVW DUFKLWHFWXUH 3DUWLFXODUO\ WKH GHVLJQHG UHGGLVK RUDQJH 2/('V DFKLHYH D VWULNLQJO\ KLJK SRZHU HIILFLHQF\ 3( RI OP : ZLWK DQ XOWUD ORZ WXUQ RQ YROWDJH RI

9 ZKLFK LV DOPRVW HTXDO WR WKH

WULSOHW HQHUJ\ OHYHO RI WKH SKRVSKRUHVFHQW UHGGLVK RUDQJH HPLWWLQJ GRSDQW 7KH 3RZHU HIILFLHQF\ RI GHYLFH ZLWK H[FLSOH[ IRUPLQJ KRVW LV HQKDQFHG DFKLHYLQJ

PDLQO\

RZQ WR ORZHU RSHUDWLQJ YROWDJH E\ QRYHO H[FLSOH[ IRUPLQJ FR KRVW FRPSDUHG ZLWK WKH UHIHUHQFH GHYLFH UROO RII WR RI

OP : 0RUHRYHU WKH 2/('V VKRZ H[WUDRUGLQDULO\ ORZ &( DW WKH EULJKWQHVV IURP

FG $ (4( PD[

&,( RI

FG P WR

FG P ZLWK WKH PD[LPDO &(

7KH GHYLFHV GLVSOD\ D JRRG UHGGLVK RUDQJH FRORU DW

FG P

QHDUO\ ZLWKRXW FRORU VKLIW ZLWK LQFUHDVLQJ

EULJKWQHVV $Q HIIHFWLYH DQG V\QHUJHWLF VWUDWHJ\ LV SURYLGHG WR GHVLJQ KLJKO\ VLPSOLILHG UHGGLVK RUDQJH 3K2/('V ZLWK ORZ HIILFLHQF\ UROO RII ZKLFK KHOSV WR ORZHU WKH FRVW DQG SRSXODUL]H 2/('V WHFKQRORJ\

2. Experimental Section &KHPLFDO VWUXFWXUHV RI DOO PDWHULDOV XHVG DUH H[KLELWHG LQ )LJ KH[DD]DWULSKHQ\OHQH KH[DFDUERQLWULOH EHQ]LQHWUL\O WULV

SKHQ\O

+EHQ]LPLGD]ROH

73%L

+$7 &1

DQG )LJ • ••

EDWKRFXSURLQH %&3



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

WUL>

S\ULG\O SKHQ

%SKHQ

,U 0'4

\O@

EHQ]HQH

DFDF

7P3\3%

7$3& DQG

Page 8 of 30

GLSKHQ\O

SKHQDQWKUROLQH

K\GUR[\TXLQROLQRODWROLWKLXP /LT ZHUH

SXUFKDVHG IURP /XPWHF &RPSDQ\ DQG XVHG DV UHFHLYHG 6$)'3$ ZDV V\QWKHVL]HG DFFRUGLQJ WR WKH OLWHUDWXUH IURP RXU FRRSHUDWLYH SDUWQHU

$OO 2/(' GHYLFHV ZHUH IDEULFDWHG RQ SDWWHUQHG LQGLXP WLQ R[LGH ,72 VXEVWUDWHV ZLWK D VKHHW UHVLVWDQFH RI

VTXDUH 7KH ,72 JODVVHV ZHUH FOHDQHG LQ D VHTXHQW

VRQLFDWLRQ EDWK RI DFHWRQH DQG LVRSURSDQRO IRU

PLQV RQH E\ RQH DIWHU WKDW EORZ

GULHG E\ QLWURJHQ JXQ WUHDWHG LQ D 89-R]RQH FKDPEHU IRU

PLQV LQ WKH HQG $IWHU

89 R]RQH WKH VXEVWUDWHV ZHUH VWUDLJKWO\ EULQJHG WR WKH YDFXXP FDYLW\ IRU 2/('V IDEULFDWLRQ 7KH PXOWL OD\HUV VXFK DV LQRUJDQLF OD\HUV RUJDQLF (/ OD\HUV DQG HOHFWURGH PDWHULDOV ZHUH RUGHUO\ JURZQ RQ WKH ,72 VXEVWUDWHV ZLWKRXW EUHDNLQJ YDFXXP a

î

c V DQG

7RUU 7KH JURZWK UDWHV RI RUJDQLF OD\HUV /LT DQG $O ZHUH DERXW

cV

c V UHVSHFWLYHO\ 7KH GHSRVLWLRQ UDWHV ZHUH WHVWHG E\ TXDUW] FU\VWDOV 7KH

SUDFWLFDO 2/('V DUHD ZHUH IDEULFDWHG E\ WKH RYHUODS RI WKH ,72 DQRGH DQG WKH $O FDWKRGH ZDV PP î PP


Page 9 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Charge balance is one of four most important factor affecting OLEDs performance EQE = Charge balance factorîExction emission rateîOptical out-coupling factorîPL efficiency). To get the fairish OLEDs performance, it is needed to optimize the thickness of HTL and ETL to make sure that the charge carrier recombination zone is located in emission zone of the luminescent materials. Based on above-mentioned understanding of the design philosophy of OLEDs, in our reference devices, ,72 +$7 &1

QP 7$3&

ZW

QP 6$)'3$ ,U 0'4

QP %SKHQ

QP /LT

QP $O

DFDF

ZW

ZW

ZW

QP WKH WKLFNQHVV RI HDFK IXQFWLRQDO

OD\HU LV UHSHDWHGO\ RSWLPL]HG WR UHDFK ILQH charge balance factor.46 Likewise, in our designed devices, ,72 +$7 &1 ,U 0'4

DFDF

ZW

QP 6$)'3$

QP %SKHQ

QP

QP /LT

QP QP

QP FR KRVW

$O

QP

WKH

WKLFNQHVV RI 6$)'3$ DV YDULDEOH YDOXH LV RSWLPL]HG WR UHDFK ILQH charge balance factor. 7KH PL[HG FR KRVW OD\HU RI 6$)'3$ %SKHQ

Z Z LQ WKH GHVLJQHG GHYLFHV helps

to achieve better charge balance in the EML,47 which can be easily tuned by controlling the ratio of the electron and hole transport materials. As the hole mobility of SAFDPA (~5.65î10-4 cm2/Vs) and the electron mobility of Bphen (~


î

í

FP 9V) are very


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 10 of 30

close, therefore, we fabricate OLEDs using SAFDPA: Bphen (1:1, w: w) mixed host. 7KH HQHUJ\ EDQG VWUXFWXUH RI WKH IDEULFDWHG 2/('V DUH H[KLELWHG LQ )LJ

+$7 &1

DQG 7$3& SOD\ UROHV DV KROH LQMHFWLRQ OD\HU +,/ DQG KROH WUDQVSRUWLRQ OD\HU +7/ UHVSHFWLYHO\ ZKLOH /LT DQG %SKHQ SOD\ UROHV DV HOHFWURQ LQMHFWLRQ OD\HU (,/ DQG HOHFWURQ WUDQVSRUWLRQ OD\HU (7/

UHVSHFWLYHO\ ,Q 3K2/(' GHYLFHV ( ) DQG *

6$)'3$ %SKHQ LV DSSOLHG DV H[FLSOH[ IRUPLQJ KRVW DQG ,U 0'4

DFDF DV GRSDQW

:KHUHDV LQ GHYLFH $ % & DQG ' FRQYHQWLRQDO KRVW GRSDQW HPLWWLQJ V\VWHP RI 6$)'3$ DQG ,U 0'4

DFDF LV DSSOLHG ZLWK GLIIHUHQW GRSLQJ UDWHV WR RSWLPL]H WKH

UHIHUHQFH GHYLFH 7KH FXUUHQW GHQVLW\ YROWDJH - 9 DQG HOHFWUROXPLQHVFHQFH (/ SURSHUWLHV ZHUH WHVWHG E\ D SKRWRPHWHU 3KRWR 5HVHDUFK 6SHFWUD6FDQ 35 FRQVWDQW FXUUHQW VRXUFH

.HLWKOH\

VRXUFHPHWHU

DVVHPEHG ZLWK D

3KRWROXPLQHVFHQFH 3/

VSHFWUD ZHUH PHDVXUHG RQ D IOXRUHVFHQFH VSHFWURSKRWRPHWHU +LWDFKL )

'HOD\HG

3/ HPLVVLRQ ZDV UHFRUGHG RQ XOWUDIDVW IOXRUHVFHQFH VSHFWURPHWHU +25,% )0 $OO

DERYH

WHVWV

ZHUH

RQ

WKH

FRQGLWLRQ

ZLWK

URRP

WHPSHUDWXUH

DQG

H[SRVHG WR DPELHQW DLU ZLWKRXW DQ\ SURWHFWLYH FRDWV 7KH RSHUDWLRQDO VWDELOLW\ RU OLIHWLPH RI WKH GHYLFHV SDFNDJHG LQ DLU ZDV WHVWHG DW D VWDUWHG EULJKWQHVV RI

FG P

DQG DW URRP WHPSHUDWXUH 7KH (/ LQWHQVLW\ DQG OLIH WLPH RI 2/('V ZHUH NHSW D UHFRUG E\ D FRPSXWHU XQWLO WKH WHVWLQJ ILQLVKHG 3. Results and Discussion 3KRWROXPLQHVFHQFH VSHFWUD RI 6$)'3$ FRPPRQ HOHFWURQ WUDQVSRUW PDWHULDOV %SKHQ %&3 7P3\3% 73%L DQG PL[HG ILOPV DUH WHVWHG DV H[KLELWHG LQ )LJ HOHFWURQ WUDQVSRUWHUV DOVR DFW DV KROH EORFNLQJ OD\HUV %&3


H9 73%,

7KHVH H9

Page 11 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


7P3\3%

H9 DQG %3KHQ

6$)'3$ DV H[KLELWHG LQ )LJ

H9 FRPSDUHG ZLWK WKH +202 OHYHO

H9 RI

7KH exciplex emission generally come from the

delocalization of electronic excitation over the two kinds of molecules and from partial electron transfer between the electron-donating and electron-accepting molecules. The charge transfer properties of the exciplex is mainly dependent on the strength of the electron-donating properties of the donor materials and on the electron affinity of the acceptor.50 Thus, it is reasonably inferred that the formation of exciplex emission in SAFDPA is own to the electron-donating ability of SAFDPA resulting from fluorene moiety. Although TmPyPB has more excellent electron transport capability than Bphen, BCP and TPBi, no red-shift PL peak from exciplex is observed, suggesting that the exciplex cannot be formed between SAFDPA and TmPyPB as exhibited in Fig. 3 (c). Additional exciplex peak is observed in the thin films of SAFDPA PL[HG with the electron-accepting material (BPhen, TPBi and BCP), providing possibility to get a spiro-exciplex-forming host-based device as exhibited in Figure 3. The higher LUMO level of SAFDPA (2.2 eV) lead to the possibility of acting as electron blocking layer and forming exciplex-forming host, simultaneously. Moreover, so as to discuss the carriers transport properties of SAFDPA and TAPC, we fabricate and discuss hole-only devices: ITO/MoO3 (10nm)/ TAPC or SAFDPA (100 nm)/MoO3 (10 nm)/Al (100 nm). The J-V properties of the devices are exhibited in supporting information Fig. S1. The hole mobility of SAFDPA is ~5.65î10-4 cm2/Vs, which is high enough to form good charge balance compared with Bphen (electron mobility =

î

í

FP 9V). Moreover,

the hole mobility of SAFDPA is comparable with other SAF-series materials.51-52 In the perspective of electron-transport capability, TmPyPB is one the best commercial small-molecule electron-transport materials (ETMs) among Bphen, BCP, TPBi and TmPyPB. The electron mobilities of Bphen, BCP, TPBi and TmPyPB are



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

î 56

í

FP 9V, î

í

FP 9V,

î

í

FP 9V and î

í

Page 12 of 30

FP 9V, respectively.53-

The distinguished electron mobility lets us choose TmPyPB as the first choice as

ETMs in designed OLEDs. Moreover, as VHHQ LQ RXU FRRSHUDWRU¶s paper,46 the higher efficiency of the devices is mainly own to the reason that TmPyPB was applied in the OLEDs promoting charge transport balance (TAPC with hole mobility of

î

í

FP 9V ). Unfortunately, the PL spectra of mixed SAFDPA: TmPyPB without red shift suggest that this mixed system do not form exciplex-forming host. Although the PL spectra of mixed SAFDPA: Bphen, SAFDPA: BCP and SAFDPA: TPBi film showing more or less red shift imply existing exciplex energy interaction between SAFDPA and ETMs (Bphen, BCP and TPBi), and Bphen possesses highest electron mobility among them which helps to enhance the charge transport balance of OLEDs. Therefore, we have choosen SAFDPA: Bphen as exciplex-forming host to design and fabricate OLEDs to primely demonstrate our OLEDs design VWUDWHJ\. Moveover, we fabricate reference OLEDs with SAFDPA: TmPyPB as non-exciplex-forming co-host OLEDs showing in Figure S1 of the supporting information to effectively support our viewpoints.


Page 13 of 30

(b)

(a) Bphen SAFDPA SAFDPA:Bphen

1.0

0.8

BCP SAFDPA SAFDPA:BCP

0.8

PL Intensity(a.u.)

PL Intensity(a.u.)

1.0

0.6 0.4 0.2

0.6 0.4 0.2

0.0 350

400

450

500

1.0

0.0

550

Wavelength(nm)

(c)

350

400

1.0

0.4

500

550

TPBi SAFDPA SAFDPA:TPBi

0.8

PL Intensity(a.u.)

0.6

450 Wavelength(nm)

(d)

TmPyPB SAFDPA SAFDPA:TmPyPB

0.8

PL Intensity(a.u.)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


0.6 0.4 0.2

0.2

0.0

0.0 350

400

450 Wavelength(nm)

500

550

350

400

450

500

550

Wavelength(nm)

The PL spectra of SAFDPA, BPhen and SAFDPA: BPhen = 1: 1 (w: w) codeposited films are exhibited in Fig. 3 (a). The mixture of SAFDPA: BPhen with 1: 1 (w: w) exhibits violet blue emission with a peak at 438 nm. The energy of this peak (~2.8 eV) nearly corresponds to the offset between the LUMO of BPhen (~3.0 eV) and the HOMO of SAFDPA (~5.6 eV), verifying that the luminescence arises from exciplex emission. The mixture of SAFDPA: BCP exhibits violet blue emission with a peak at 413 nm as exhibited in Figure 3 (b). This peak energy (~3.0 eV) hardly corresponds to the offset between the LUMO of BCP (~3.0 eV) and the HOMO of SAFDPA (~5.6 eV). The PL spectra of BCP (Fig. 3 (b)) show secondary peaks at 520 nm own to the effect of excimers, dimers or other aggregates58 which destroy by doping SAFDPA. The PL



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 30

spectra of mixture films of SAFDPA: TmPyPB with 1: 1 (w: w) do not show the red shift relative to the PL spectrum of SAFDPA as exhibited in Fig. 3 (c). The mixture of SAFDPA: TPBi exhibits violet blue emission with a peak at 413 nm as exhibited in Fig. 3 (d). The peak energy (~3.0 eV) hardly corresponds to the energy offset between the LUMO of TPBi (~3.0 eV) and the HOMO of SAFDPA (~5.6 eV). The PL spectra of SAFDPA: BCP and SAFDPA: TPBi imply that the mixture may not form exciplex emission. Fig. 4. VKRZV delayed PL emission intensity of mixed SAFDPA: TmPyPB (1:1, Z Z ¿OPV DQG PL[HG 6$)'3$ %SKHQ

, Z Z ¿OPV ZKLFK LQGLFDWH WKDW WKH

exciton lifetime of SAFDPA: Bphen co-host is remarkably longer than the exciton lifetime of SAFDPA: TmPyPB films supporting the formation of SAFDPA: Bphen exciplex emission. One leaf is not as same as another (exciplex-forming systems)5961

in the world, even so, we find a similar and comparable known exciplex-forming

systems: TCTA: B3PYMPM (), to our SAFDPA: Bphen, which can be used to design high efficiency exciplex emission OLEDs.62 Moreover, SAFDPA: Bphen own suitable energy state following three rules proposed in the Introduction part:

$ VXLWDEOH

ORZHVW XQRFFXSLHG PROHFXODU RUELWDO /802 OHYHO RI 6$)'3$ PDWFKLQJ :) RI ,72 DQRGH LQ FRQYHQWLRQDO 2/('V IRU WKH SXUSRVH RI DYRLGLQJ WKH UHTXLUHPHQW IRU PXOWLSOH WUDQVSRUW OD\HUV 7$3&

7 OHYHO RI 6$)'3$ DQG %SKHQ DUH KLJKHU WKDQ WKDW RI D

UHG SKRVSKRUHVFHQW GRSDQW WR FRQILQH WKH UHFRPELQDWLRQ ]RQH DQG XWLOL]H WKH HQHUJ\ WUDQVIHU IURP WKH H[FLSOH[ WR WKH GRSDQW DQG

'HHSHU +202 KLJKHVW RFFXSLHG

PROHFXODU RUELWDO RI %SKHQ DQG KLJKHU /802 RI 6$)'3$ FRQILQLQJ H[FLWRQ UHFRPELQDWLRQ ]RQH WR DYRLG TXHQFKLQJ GXULQJ FKDUJH WUDQVSRUW 7KHUHIRUH ZH GHVLJQ


Page 15 of 30

3K2/('V EDVLQJ RQ FKDUDFWHULVWLF RI QRYHO H[FLSOH[ IRUPLQJ KRVW WR VLPSOLI\ GHYLFH VWUXFWXUH DQG HQKDQFH WKH SHUIRUPDQFH RI GHYLFHV

4

10

50

(b) 35

Luminance (cd/m2) Current Efficiency (cd/A)

Current Density (mA/cm2)

(a) 40

30

3

10 30 20

25 20

2

10 10 0 5

6

7

10

0

10

20

30

40


Voltage(V)

(d)

25

Normalized Intensity(a.u.)

(c)

4

15 10

1

3

Power Efficiency (lm/W)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


20

15

10

5 0

10

20

30

40

1.0 0.8

Device A Device B Device C Device D

@ 5 mA/cm2

0.6 0.4 0.2 0.0

350 400 450 500 550 600 650 700 750 800


Wavelength (nm)

7R RSWLPL]H WKH UHIHUHQFH GHYLFH SHUIRUPDQFH DPRQJ GHYLFHV $ % & DQG ' WKH



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

GRSLQJ SURSRUWLRQ RI ,U 0'4 ' WR

GHYLFH $ GHYLFH %

Page 16 of 30

DFDF LQWR 6$)'3$ ZDV GHFUHDVHG IURP ZW

GHYLFH &

UHSRUWHG JXHVW KRVW UHG 3K2/('V UHVHDUFK

ZW

GHYLFH

EDVHG RQ WKH SUHYLRXVO\

7KH FXUUHQW GHQVLW\ YROWDJH OXPLQDQFH

- 9 / FKDUDFWHULVWLFV HIILFLHQF\ DQG (/ VSHFWUD RI UHIHUHQFH GHYLFHV DUH exhibited LQ )LJ

$V exhibited LQ )LJ

D DQG G - 9 FKDUDFWHULVWLFV DQG QRUPDOL]HG (/ VSHFWUD

VKRZ WLQ\ FKDQJHV ZLWK WKH GHFUHDVH LQ GRSLQJ SURSRUWLRQ RI ,U 0'4

DFDF IURP

WR

SURSRUWLRQ RI

ZKLOH EULJKWQHVV LQFUHDVHV WR WKH SHDN YDOXH ZLWK

,U 0'4

DFDF EHIRUH GHFOLQLQJ EHFDXVH RI WKH VWUHQJWKHQLQJ RI WULSOHW WULSOHW

DQQLKLODWLRQ WULSOHW SRODURQ TXHQFKLQJ DQG ILHOG LQGXFHG TXHQFKLQJ ZLWK KLJKHU SURSRUWLRQ RI G\H $V exhibited LQ )LJ

E DQG F

GRSHG UDWH RI ,U 0'4

DFDF

UHDFK WKH PD[LPXP YDOXH RI 3( DQG &( LQ RXU RSWLPL]HG UHIHUHQFH UHG 3K2/('V 7KH GHYLFH SURSHUWLHV RI WKH UHIHUHQFH 3K2/('V LV VXPPDUL]HG LQ 7DEOH PD[LPXP &( DQG SRZHU HIILFLHQF\

&

3

RI

FG $ (4(

OP : UHVSHFWLYHO\ ZLWK WKH OLJKW HPLVVLRQ SHDNV RI UHIHUHQFH UHG 3K2/('V LV ORZ WR

7DEOH

ZLWK

DQG

QP 7KH &( UROO RII RI

GRSLQJ SURSRUWLRQ

3HUIRUPDQFH VXPPDU\ RI WKH UHIHUHQFH UHG 3K2/('V


GHSLFWLQJ WKH

Page 17 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


,Q WKH SHUVSHFWLYH RI KROH WUDQVSRUWDWLRQ DV H[KLELWHG LQ )LJ DW WKH +$7 &1 DQG 7$3& LQWHUIDFH DQG

WKHUH LV

H9 EDUULHU

H9 EDUULHU DW WKH LQWHUIDFH EHWZHHQ 7$3&

DQG 6$)'3$ DORQJ +202 OHYHO ,QVHUWLQJ DQ DGGLWLRQDO 7$3& OD\HU ZLOO VHSDUDWH WKH LQMHFWLRQ EDUULHU RI

H9 EHWZHHQ +$7 &1 DQG 6$)'3$ WR WZR VPDOOHU EDUULHUV DQG

WKXV HQKDQFH KROH LQMHFWLRQ +RZHYHU KROH WUDQVSRUW FDSDFLW\ RI VSLUR EDVHG PDWHULDOV DQG OHVV QXPEHU RI KHWHURMXQFWLRQV PDNH XS D OLWWOH EDUULHU LQWURGXFHG E\ UHPRYLQJ 7$3& )RU HQHUJ\ WUDQVIHU SURFHVV H[KLELWHG LQ )LJ

D LQ WKH UHIHUHQFH GHYLFH WKH

H9 WULSOHW VWDWH JDS EHWZHHQ KRVW 6$)'3$ DQG JXHVW ,U 0'4

DFDF SULPHO\

FRQILQHV WKH H[FLWRQ HQHUJ\ WR OXPLQHVFH RQFH WKH HQHUJ\ LV VXFFHVVIXOO\ WUDQVIHUUHG WR HQHUJ\ VWDWH RI ,U 0'4 6$)'3$ 7

DFDF 7$3& 7

H9 ZLWK KLJKHU 7 WKDQ KRVW PDWHULDO

H9 VHHPV WR EH XQQHFHVVDULO\ DFWLQJ DV HQHUJ\ EORFNLQJ OD\HU

7KHUHIRUH DV GHPRQVWUDWHG LQ )LJ

E LQ RXU KLJKO\ VLPSOLILHG GHVLJQHG UHGGLVK

RUDQJH 3K2/('V ZLWKRXW WUDGLWLRQDO KROH WUDQVSRUW PDWHULDO 7$3& ZH HPSOR\ QRYHO VSLUR H[FLSOH[ IRUPLQJ KRVW ZKLFK VKRXOG VKRZ ORZHU WULSOHW VWDWH WKDQ WZR PL[HG H[FLSOH[ KRVWV 6$)'3$ DQG %3KHQ HQHUJ\ WUDQVIHU URXWH WR ,U 0'4

7KLV ORZHU H[FLSOH[ WULSOHW VWDWH RIIHUV D VPRRWK

DFDF DQG IXUWKHU ORZHUV WKH HQHUJ\ RI OXPLQHVFHQFH

V\VWHP FRPSDUHG ZLWK KRVW JXHVW OXPLQHVFHQFH V\VWHP ZKLFK KHOSV WR DFKLHYH ORZ &( UROO RII RI RXU GHVLJQHG 3K2/('V RZQ WR HQKDQFHG HIILFLHQF\ DQG VWDELOLW\ XQGHU KLJK YROWDJH ,Q RUGHU WR FRQILUP WKH SURSRVHG VWUDWHJ\ VLPSOLILHG GHVLJQHG UHGGLVK RUDQJH 3K2/('V KDYH EHHQ IDEULFDWHG DQG WHVWHG DV IROORZV



4

(b) 36

10 40

3

30

10

20 2

10

10 0

Luminance (cd/m2) Current Efficiency (cd/A)


(a) 50

1

2

3

4

5

6

7

8

34 32 30 28 26 24 22 20

10

0

10

20

30

40


Voltage(V)

(c)

(d) Normalized Intensity(a.u.)

33

Power Efficiency (lm/W)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 30

30 27 24 21 18 15 12 0

10

20

30

40 2

Current Density (mA/cm )

1.0 0.8

Device E Device F Device G Device B

@ 5 mA/cm2

0.6 0.4 0.2 0.0

350 400 450 500 550 600 650 700 750 800

Wavelength (nm)


Page 19 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


7DEOH

)LJ

(/ &KDUDFWHULVWLFV RI WKH GHVLJQHG 'HYLFHV

D VKRZV D FRPSDULVRQ RI WKH - 9 / FKDUDFWHULVWLFV RI WKH GHVLJQHG GHYLFHV

( ) * ZLWK WKDW RI WKH UHIHUHQFH GHYLFH % ,W FDQ EH VHHQ WKDW DW WKH VDPH YROWDJH WKH VSLUR H[FLSOH[ IRUPLQJ KRVW UHGGLVK RUDQJH 3K2/('V VKRZ KLJKHU EULJKWQHVV DQG FXUUHQW WKDQ WKRVH RI WKH FRQYHQWLRQDO GHYLFH ZLWK 7$3& DV KROH WUDQVSRUW OD\HU )RU H[DPSOH DW D FXUUHQW GHQVLW\ RI

P$ FP WKH GULYLQJ YROWDJHV IRU % DQG ) GHYLFHV

DUH

9 ZLWK WKH EULJKWQHVV RI

FG P DQG

9 ZLWK WKH EULJKWQHVV RI

FG P

UHVSHFWLYHO\ 7KH ORZHU GULYLQJ YROWDJH DQG KLJKHU EULJKWQHVV DUH DWWDLQHG E\

VSLUR H[FLSOH[ IRUPLQJ KRVW 3K2/('V 7KLV FDQ EH PDLQO\ DWWULEXWHG WR WKH VXSHULRULW\ RI QRYHO H[FLSOH[ FR KRVW DW ORZ GULYLQJ YROWDJH

0RUHRYHU WKH +202 RI 6$)'3$

PDWFKHV SULPHO\ ZLWK WKH HQHUJ\ OHYHO RI +$7 &1 ,72 DYRLGLQJ DGGLWLRQDO WUDS SURGXFWLRQ E\ WKH H[WUD LQWHUIDFH RI 7$3& GXULQJ WKH KROH WUDQVSRUWLQJ SURFHVV )LJ E DQG F VKRZ WKH &( DQG 3( ZLWK FXUUHQW GHQVLW\ IRU GHVLJQHG GHYLFH VWUXFWXUHV UHVSHFWLYHO\ $SSDUHQWO\ WKH (/ FKDUDFWHULVWLF VSHFWUD )LJ

G DQG &,( 7DEOH

IRU ERWK WKH VSLUR H[FLSOH[ IRUPLQJ KRVW LQFRUSRUDWHG 3K2/('V DQG UHIHUHQFH GHYLFH



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 30

VWUXFWXUHV DUH DOPRVW WKH VDPH RZQ WR WKH IDFW WKDW WKH FDUULHUV UHFRPELQDWLRQ ]RQH LV SULPHO\ OLPLWHG ZLWKLQ WKH HPLVVLYH OD\HU 0RUHRYHU ZH RSWLPL]HG WKH GHYLFH SHUIRUPDQFH DPRQJ GHYLFHV ( ) DQG * $V WKH WKLFNQHVV RI 6$)'3$ GHFUHDVHV IURP QP WR

QP WKH 3( DQG &( ILUVWO\ LQFUHDVH WKDQNV WR WKH HTXLOLEULXP RI FDUULHUV

LQMHFWLRQ ZLWK WKH

QP 6$)'3$ DQG WKHQ GHFUHDVH RQ DFFRXQW RI WKLQQHU 6$)'3$

OHDGLQJ WR LPEDODQFH RI FDUULHUV LQMHFWLRQ DQG PLVPDWFK RI RSWLFDO ILHOG ZLWK DQ XOWUD ORZ WKUHVKROG YROWDJH RI

9 ZKLFK UHYHDOHG WKDW QRYHO VSLUR EDVHG H[FLSOH[

IRUPLQJ KRVWV LV XVHIXO LQ RSWLPL]LQJ WKH FDUULHUV¶ ORFDWLRQ DQG UHFRPELQDWLRQ ]RQH SURPRWLQJ WKH HQHUJ\ WUDQVIHU IURP FR KRVW WR HPLWWHU EHFDXVH RI WKHLU ORZHU /802 OHYHOV DQG VXLWHG WULSOHW HQHUJLHV LQ VLPSOLILHG GHYLFH $V H[KLELWHG LQ 7DEOH FXUUHQW DQG SRZHU HIILFLHQFLHV DUH

FG $ (4(

UHIHUHQFH GHYLFH DUH H[KLELWHG LQ )LJ

&

3

WKH SHDN

IRU WKH VSLUR H[FLSOH[ IRUPLQJ KRVW 3K2/('V

DQG FG $ (4(

OP : UHVSHFWLYHO\ ZKHUHDV WKRVH IRU WKH DQG

OP : UHVSHFWLYHO\ DV

3DUWLFXODUO\ WKH 3( RI WKH GHVLJQHG UHGGLVK RUDQJH 3K2/('V ZLWK

H[FLSOH[ IRUPLQJ KRVW HQKDQFH XS WR

PDLQO\ RZQ WR ORZHU RSHUDWLQJ YROWDJH

FRPSDUHG ZLWK UHIHUHQFH GHYLFH DV H[KLELWHG LQ WKH )LJ

2ZQ WR WKH UHVWUDLQ RI 77$

LQ GHVLJQHG 3K2/('V E\ ORZHU GRSSLQJ DQG H[FLSOH[ KRVW WKHLU &( UROO RII LV ORZ DV WR

ZLWKLQ WKH EULJKWQHVV UDQJH RI

FG P WR

FG P


Page 21 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


6SHFWUDO FKDQJHV RI DOO WKH 2/('V ZLWK YDULRXV FXUUHQW GHQVLW\ DUH VWXGLHG E\ GUDZLQJ WKH (/ VSHFWUD E\ WKHLU FRUUHVSRQGLQJ FXUUHQW GHQVLWLHV )LJ UHODWLYH LQWHQVLW\ (/ VSHFWUD RI WKH 2/('V XVLQJ ,U 0'4 SURSRUWLRQ RI ZW 7KH LQVHW LQ )LJ

DW WKH FXUUHQW GHQVLWLHV RI

DQG

H[KLELWV WKH FRORU VKLIWV LQ WKH &,(

VKRZV WKH

DFDF DV GRSDQW ZLWK P$ FP UHVSHFWLYHO\

FKURPDWLFLW\ FRRUGLQDWHV

7KH 2/('V VKRZ WLQ\ FKDQJHV LQ WKH &,( FRORU FRRUGLQDWHV ZLWK WKH PL[HG SURSRUWLRQ RI

ZW DW

ZLWK WKH UHG GRSDQW FKDQJLQJ IURP

DW

FG P WR

FG P 7KH SHDNV RI WKH (/ VSHFWUD RI WKH GHYLFHV DUH VDPH ZLWK VWDEOH

&,( FRRUGLQDWHV DV WKH FXUUHQW GHQVLW\ LQFUHDVHV



100 2

Designed OLED @3051cd/m 14.1h 2 Reference OLED @2942cd/m 10.7h

90

Normalized luminance (a.u.)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 22 of 30

80

70

60

50

0

2

4

6

8

10

12

14

16

18

20

Time (hours)

)LJ

VKRZV WKH RSHUDWLRQDO OLIHWLPH RI UHGGLVK RUDQJH 3K2/(' ZLWK VSLUR

H[FLSOH[ IRUPLQJ KRVW DQG UHIHUHQFH GHYLFH 7KH OLIHWLPH RU VWDELOLW\ RI WKH 2/('V ZHUH WHVWHG DW WKH VDPH LQLWLDO EULJKWQHVV RI

FG P UDWKHU WKDQ JHQHUDO

FG P

WR DFFHOHUDWH WKH DJLQJ WHVW ,W LV VKRZQ FRPSDUHG ZLWK WKH UHIHUHQFH 2/(' WKH VSLUR H[FLSOH[ IRUPLQJ KRVW 3K2/('V VKRZ ORQJHU RSHUDWLRQDO OLIHWLPH ZKLFK PDLQO\ PHDQV OHVV LQWHUIDFLDO GHIHFWV E\ UHPRYLQJ DQ DGGLWLRQDO OD\HU RI 7$3& DQG LQ DGGLWLRQ WKH FR KRVW KHOSV WR ORZHU H[FLWRQV DFFXPXODWLRQ ZKLFK GHVWUR\ RUJDQLF LQWHUIDFH 0RUHRYHU OHVV KRPR MXQFWLRQ KHOSV WR LPSURYH GHYLFH OLIHWLPH 7 DWWDLQ D

GHFD\ RI OXPLQHVFHQFH

7

PHDQV WKH WLPH WR

RI WKH GHYLFH LPSURYHV IURP

KRXUV WR

KRXUV E\ DSSO\LQJ VSLUR H[FLSOH[ IRUPLQJ KRVW $OWKRXJK WKLV LV QRW WKH NH\ SRLQW QHHGHG WR LOOXVWUDWH OLWKLXP LRQ GRSLQJ FDQ VROYH FU\VWDO RI %SKHQ ZKHQ WKH WKLFNQHVV RI %SKHQ LV PRUH WKDQ

QP KHOSLQJ WR IXUWKHU ORZHU WKH RSHUDWLQJ YROWDJH DQG


Page 23 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


LPSURYH GHYLFH OLIHWLPH

4. Conclusions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

ASSOCIATED CONTENT

AUTHOR INFORMATION Corresponding Author * Hong Meng. Email: [email protected]

* Liang-Sheng Liao. Email: [email protected]



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 24 of 30

Supporting Information: Experimental section; Performance of reference OLEDs with SAFDPA: TmPyPB as non-exciplex-forming co-host showing in Figure S1; The current density-voltage (J-V) curves for the hole-only devices showing charge transporting properties of the SAFDPA in Figure S2.

ACKNOWLEDGMENT This work is supported by the National Natural Science Foundation of China (61575136, 51035008, 51373075), National Basic Research Program of China (973 Program, 2015CB932200). This project was also funded by the Collaborative Innovation Center of Suzhou Nano Science and Technology, by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and by Shenzhen Key Laboratory of Organic Optoelectromagnetic Functional Materials of Shenzhen Science and Technology Plan (ZDSYS20140509094114164).

5HIHUHQFHV íX

^Z vU •XV µŒŒ}Á•U WX XV µo}À] U sXV &}ŒŒ •šU ^X ZXV dZ}u‰•}vU DX XU dZŒ

>]PZšr u]šš]vP îX

íõõóU îóò ~ñïîí•U îììõrîìííX

• Á]šZ (oµ}Œ • vš šµ

((] ] v ÇX E šµŒ îììõU ðñõ ~óîðð•U îïðrîïôX

^µvU zXV &}ŒŒ •šU ^X ZXU ,]PZr ((] ] v Ç ÁZ]š }ŒP v] o]PZš u]šš]vP

‰Z}•‰Z}Œ • vš u]••]}v o Ç Œ•X ‰‰o] ðX

o U KŒP v]

Z ]v l U ^XV >]v v ŒU &XV ^ ZÁ ŒšÌU 'XV ^ ] o ŒU EXV t oÌ ŒU µ•• uU XV > }U šš Œ• îììóU õí ~îò•U îòïñìïX

ŒU DX 'XV t vPU •X XV Y]µU :XV 'Œ ]v ŒU DX dXV WµÌÌ}U X WXV >]µU •X tXV >µU •X ,XU Zo}Œ]v š

/v ]µu d]v KÆ]

o šŒ}

• Á]šZ ,]PZ t}Œl &µv š]}v (}Œ KŒP v]

À]

}u‰ š] ]o]šÇX ^ ] v

îìííU

ïïî ~òìïî•U õððrõðóX ñX

D U XU tZ]š K>

XV •]••]•U 'XV D U ZXU òX

À] •X /v , v

}}l }(

À v

>]PZš]vP d Zv}o}PÇU < Œo] lU ZXV ^µvU Xr

•X ^‰Œ]vP Œ /vš Œv š]}v o Wµ o]•Z]vPW Z uU îìíòV ‰‰ írïðX

yµU dXV z vPU DXV >]µU :XV tµU yXV DµŒš Ì U /XV , U 'XV D vPU ,XU t]

Œ}oor}(( (oµ}Œ • vš }ŒP v] o]PZš u]šš]vP

À] •

•

}v }µ o µv }‰

}o}ŒrŒ vP šµv

o

v o}Á

µošŒ šZ]v u]šš Œ•X KŒP v]

o šŒ}v] • îìíòU ïóU õïrõõX óX

W Œ ‰] Zl U /X &XV W Œ ‰] Zl U X &XV D vPU ,XV tµ oU &XU >]PZšr u]šš]vP W}oÇšZ]}‰Z v •X


À v

Page 25 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


D š Œ] o• îììñU íó ~íõ•U îîôírîïìñX ôX

>µ}U X zXV zµU >X DXV D vU :X yXV >]µU dX >XV >]U :X :XV yµU dXV >]µU •XV t vPU •X XV >µU •X ,XU

•šŒµ šµŒ Á]šZ šµv

o

o šŒ] o v }‰š] o ‰Œ}‰ Œš] • (}Œ }ŒP v] ‰Z}š}À}oš ]

]r(µv š]}v o

oo•X :}µŒv o }( ‰‰o]

WZÇ•] • îìíïU ííï ~îî•U îîðñìòX õX

D šZ Á•U ^XU WZÇš} ZŒ}u ru

u š šZ íìX

v ÀµoP Œ]• Ç

XV t vPU YXV •Z vPU •XV •}µU dXV Y]vU :XV D U

XU

^]u‰o

WZ}•‰Z}Œ • vš

Z u] îììôU íîì ~ðî•U ôîîðrôîîóX

íîX z vU &XrtXV Z]µU XrzXV >]vU /X &XV d vPU XrDXV >]vU yXr,XU WríôïW ((] ] vš ]•ZrKŒ vP

Z]PZ˜]vš v•]šÇU

v > • Œ dZ Œ ‰Ç îììïU ñ ~î•U ííírííóX

Ì}o lKÆ ] Ì}o ,Ç Œ] D}o µo W v Æ oo vš ]‰}o Œ ,}•š (}Œ 'Œ v v Z •X vP Á v š

Z

o]PZš • v•]vP À}oÀ • š}

}o}PÇ îììòU íñ ~íî•U ïðôïrïñìïX

(( š]À šŒ šu vš }(

v ðìñtðîì0vu o]PZš •}µŒ X :}µŒv o }( }•u š]

ííX d }U zXV t vPU YXV z vPU Œ

À o}‰u vš ]v o v ‰o vš•W Œ

ou vU DXV ^o šl]v U DXV , ŒšZU zXU dZ

v ŒŒ}Á

K>

] š

Z oo vP • }( Z vP]vP o]PZš vÀ]Œ}vu vš•X D}o µo Œ

v Z

KŒP v] >]PZšr u]šš]vP

‰ oµ U oµ U 'Œ vU z oo}ÁU

µ•]vP îUór ]‰ÇŒ v •‰]Œ}(oµ}Œ v ~ W^&• •

À]

&oµ}Œ • vš u]šš]vP ,}•šX ^/ ^Çu‰}•]µu ]P •š }( d Zv] o W ‰ Œ• îììóU ïô ~í•U ôôïrôôóX íïX dµvPU zXr>XV >

U ^XrtXV Z]U zXV d }U zXrdXV Z] vU Xr,XV Z vPU zXrDXV Z}µU WXrdXV W vPU ^XrDXV >]µU Xr^XU

KŒP v] o]PZšr u]šš]vP ]}

•

}v Z ŒP rv µšŒ o K•~]]• u]šš Œ•W P v Œ š]}v }( • šµŒ š

•

Œ

u]••]}v Á]šZ À ŒÇ Z]PZ Æš Œv o ‹µ všµu ((] ] v ÇX :}µŒv o }( D š Œ] o• Z u]•šŒÇ îììñU íñ ~ð•U ðòìr ðòðX íðX XV EP}U dXV Z i vU šš Œ• îììîU ôí ~í•U íòîríòðX

íñX ^}] Z]U tXV E} µZ]Œ}U /XV :µvi]U ]µU zXV t vPU zXV ŒÇ U DX ZXU s ŒÇ ,]PZ ((] ] v Ç KŒ vP rZ À] • Á]šZ >}Á Z}oorK(( š ,]PZ >µu]v v

•

}v v /

>]PZšr u]šš]vP

o ,}•št'µ •š ^Ç•š u }v•]•š]vP }( dÁ}

E}À o WZ}•‰Z}Œ • vš /Œ] ]µu }u‰o Æ • Á]šZ ]‰}o Œ dŒ v•‰}ŒšX

À v

&µv š]}v o D š Œ] o• îìíðU

îð ~ðó•U óðîìróðîòX íõX ,µ vPU :XV W( ](( ŒU DXV t Œv ŒU o šŒ}oµu]v • vš

XV

o} ZÁ]šÌU :XV > }U ]µU ^XU >}ÁrÀ}oš P

À] • µ•]vP ‰]v •šŒµ šµŒ •X ‰‰o]

îìX , U 'XV W( ](( ŒU DXV > }U šš Œ• îììîU ôì ~í•U íïõríðíX lU :XU ,]PZr ((] ] v Ç v

• Á]šZ }µ o r u]••]}v o Ç Œ•X

WZÇ•] • > šš Œ• îììðU ôñ ~íó•U ïõíírïõíïX

îíX '}vPU ^XV Z vPU zXr>XV tµU µU •Xr,XV ^}vPU XV z vPU XU ,]PZrW}Á Œr ((] ] v Ç oµ o šŒ}‰Z}•‰Z}Œ • v

v

o

Ç šZ ^Çv ŒP]•š]

}u ]v š]}v }( WZ}•‰Z]v rKÆ]

r

•

,}•š v

o šŒ}vrdŒ v•‰}Œš]vP D š Œ] o•X Z u]•šŒÇ }( D š Œ] o• îìíðU îò ~ï•U íðòïríðóìX îîX ^µU ^Xr:XV ^ •

U ,XV WµU zXr:XV E l Ç u U ]µU DXV ^µU ^Xr:XV t vPU zXr&XV >}U Xr XV >] vU XV s}oš P

v Z

µ

((] ] v Ç Z}oorK((X

&µv š]}v o D š Œ] o• îìíðU îð ~îí•U ïîòôrïîóñX

À v

îðX t vPU :XV Z vU :XV Y] }U yXV o•Z ZŒ]U ^X DXV Z u t Œu tZ]š KŒP v] >]PZšr u]šš]vP ]} ‰‰o]

• Á]šZ hošŒ o}Á K‰ Œ š]vP

U dXV D U XU ^]u‰o r^šŒµ šµŒ

WZ}•‰Z}Œ • vš

• Á]šZ ,]PZ W}Á Œ ((] ] v Ç v >}Á ((] ] v Ç Z}oor}((X

^

• îìíòU ô ~íò•U íììõïríììõóX

D š Œ] o• ˜ /vš Œ(

îñX tµU Xr,XV ^Z]ZU WXr/XV ^ZµU Xr&XV Z]U zXU ,]PZoÇ ((] ] vš Œ (oµ}Œ v ršŒ]‰Z vÇo u]v Z}•š }‰

}ŒP v] o]PZšr u]šš]vP

À] •

•

}v

WZÇ•] • > šš Œ• îììôU õî ~îï•U

Á]šZ v K•~//• ‰Z}•‰Z}ŒX ‰‰o]

îïïïìïX îòX

Z] vU Xr,XV ,•µU &XrDXV ^ZµU Xr&XV Z]U zXU ((] ] vš Œ

•

îóX : }vU tX ^XV W ŒlU dX :XV

‰‰o]

(oµ}Œ v r

U ZXV : vPU :XV XV >]U >XV :] vPU zXV µ]U ZXV >]U zXV •Z }U yXV •Z vPU ,XU Z Œ v

(Œ}u

o šŒ}v] • îììõU íì ~ñ•U ôóírôóòX

]‰}o Œ Z}•š u š Œ] oX KŒP v]

‰Z}•‰Z}Œ • vš K>

o šŒ}‰Z}•‰Z}Œ • v

Œ (}Œ ((] ] vš Z

/Œ] ]µu }u‰o Æ

ŒšZ }u‰o Æ • o šŒ}v dŒ ‰‰ Œ

•

o šŒ}oµu]v • vš

À] •X

îõX >]U zXV •Z}µU >XV µ]U ZXV :] vPU zXV •Z }U yXV >]µU tXV •ZµU YXV µ]U zXV •Z vPU ,XU ,]PZ ‰ Œ(}Œu v }ŒP v]

^

• îìíñU ó ~îõ•U íòìðòríòìñïX

D š Œ] o• ˜ /vš Œ( o šŒ}oµu]v • vš

À] •

•

}v

šŒ]À o vš ]Œ] ]µu }u‰o Æ Á]šZ •š ‰Á]•

Œ

v ŒPÇ o À o•X

À v • îìíòU ò ~óñ•U óíîôîróíîôòX

Z^

ïìX ^µU ^Xr:XV '}vu}Œ]U XV ^ • À] • , À]vP

ŒŒ] Œr v

U ,XV ]PZšr u]šš]vP

µ

((] ] v Ç Z}oorK((X

À v

D š Œ] o• îììôU îì ~îí•U ðíôõrðíõðX ïíX >]U yXr>XV KµÇ vPU yXV >]µU DXV ' U •XV W vPU :XV

}U zXV ^µU ^Xr:XU ,]PZoÇ ((] ] vš •]vPo r v uµoš]r

u]••]}vro Ç Œ (oµ}Œ • všl‰Z}•‰Z}Œ • vš ZÇ Œ] ÁZ]š }ŒP v] o]PZšr u]šš]vP ]}

• Á]šZ €•]u]o Œ•îì9

Æš Œv o ‹µ všµu ((] ] v ÇX :}µŒv o }( D š Œ] o• Z u]•šŒÇ îìíñU ï ~ïñ•U õîïïrõîïõX ïîX ^µvU :X tXV ]µU ^Xr,XV Z}µU WXrdXV ,µvPU zXrdXV t}vPU o v

h•]vP

dŒ] Ì]v r

'µ •š }v

PPŒ P š]}v }( šZ

,}•š

Ç Æ ]š}vtW}o Œ}v

/vš Œ š]}v• v /š• (( š• }v šZ ^š ]o]šÇ }( WZ}•‰Z}Œ • vš KŒP v] >]PZšr u]šš]vP ‰‰o] ïñX

D š Œ] o• ˜ /vš Œ(

•

• Á]šZ

]‰}o Œ šŒ v•‰}Œš o Ç ŒX ‰‰o]

KŒP v] >]PZšr u]šš]vP

ïóX ^ ]v}U zXV /v}u š U ^XV ^ • o Ç

^

U ,Xr XV ^}U &XV ^Z vU :XV z vPU :XU KŒP v] o]PZšr WZÇ•] • > šš Œ• íõõõU óñ ~î•U íóîríóðX

Ì]ÌU ,XV W}‰}À] U •X XV ,µU EXryXV ,}ŒU XrDXV yµU 'XU

š]À š

À] •X

• îìíòU ô ~îî•U íðìôôríðìõñX

Z}}vPU sXr XV ^Z]U ^XV µŒo ••U :XV ^Z] ZU Xr>XV >

u]šš]vP ]} ïòX

•

• îìíòU ô ~ó•U ðôíírðôíôX

&oµ}Œ • v

À] •X ^ ] v

PŒ

š]}v D Z v]•u }( ^u oo D}o µo r

íõõõU îôï ~ñðìõ•U íõììríõìîX

U ,XV WµU zXr:XV XV D] }U :XV ,µU •XV ^Z }U ^XV >]U XV DµŒš Ì U /XV D vPU ,XU hvo} l]vP šZ ‰}š vš] o }( ]l š}‰ÇŒŒ}o}‰ÇŒŒ}o r

•

•}o Œ

oo• Ç ‰Œ r•}oÀ vš vv o]vP u šZ} ]v oor•}oµš]}v ‰Œ} ••]vPX Z^

À v • îìíòU ò ~ñô•U ñïñôórñïñõñX ððX

o }U DX XV

Z]U XV &}ŒŒ •šU ^X ZXU dŒ v•] vš v oÇ•]• }( }ŒP v]

dŒ v•] vš v oÇ•]• }( šŒ]‰o šršŒ]‰o š vv]Z]o š]}vX WZÇ•] o Z À] Á

o šŒ}‰Z}•‰Z}Œ • v X //X

îìììU òî ~íò•U íìõòóríìõóóX

ðñX Z ]v l U ^XV t oÌ ŒU }U XV µ]U >Xr^XV ' }U Xr,XV Z vU ,XV >]U YXV :] vPU •XrYXV >] }U >Xr^XU }všŒ}o }( }viµP š]}v

PŒ

À] W}•]š]}v vP]v Œ]vP š} ,]PZoÇ ((] ] vš WZ}•‰Z}Œ • vš ,}•š D š Œ] o•X KŒP v]

> šš Œ• îìíðU íò ~íð•U ïóðôrïóñíX ðóX

Z}‰Œ U EXV ^Á v• vU :X ^XV W}o]l Œ‰}ÀU XV }•]u

((] ] v Ç

v

o}Á Œ}oor}((

Œ Z]š šµŒ X ‰‰o]

oµ

‰Z}•‰Z}Œ • vš }ŒP v] o]PZšr u]šš]vP

X

XU ,]PZ

À] • µ•]vP u]Æ

Z}•š

WZÇ•] • > šš Œ• îìíìU õó ~ï•U ìïïïìðX

ðôX •Z vPU >XV •µU &Xr^XV

vPU zXr>XV /P

]v KŒP v] >]PZšr u]šš]vP ]} ]((µ•]}vM

• µU >XV ^}U &XV W u ‰ Œµu U

Œ]U &XV t vPU •Xr] }U >Xr^XU KŒ]P]v }( vZ v

• Á]šZ v o šŒ}vr

‰š}Œ }‰]vP > Ç ŒW ‰rdÇ‰

,}o /vi š]}v

}‰]vP }Œ /vš Œ( ] o

• ‰‰o D š Œ /vš Œ îìíñU ó ~îî•U ííõòñrííõóíX

ðõX d vPU yXV Y] vU DXV •Z}µU XrzXV ]vPU >XV ,µU zXV >] }U >Xr^XU š}o Œ š]vP •µ •šŒ š

}vš u]v š]}v }v šŒ v•‰ Œ vš o šŒ}

•µŒ(

u} ](] š]}v o Ç Œ

• }( }ŒP v]

o šŒ}v]

‰

o }(

À] •X KŒP v]

o šŒ}v] • îìíòU îôU îíórîîðX ñìX > ]U ^Xr>XV d}vPU YXryXV

Xr^XU

]•š]v š

Œ]À š]À • ]v oµ }ŒP v] o]PZšr u]šš]vP

À] •X

Z vU DXrzXV EPU dXrtXV >}U DXr&XV >

o šŒ}oµu]v • vš ‰Œ}‰ Œš] • }( šŒ]‰Z vÇo u]v

U ^XrdXV >

U

:}µŒv o }( D š Œ] o• Z u]•šŒÇ îìííU îí ~ð•U íîìòríîííX ñíX D]l] U dXV ^ l]U XV D •µ (µoo Œ v u}v} v

U ,XV /lµu U EXV

• h•]vP Z À Œ•

• ‰‰o D š Œ /vš Œ îìíðU ò ~íñ•U

4 ^td }( Œ}µv • Œ}X

ííõìórííõíðX òìX

Z Œ‰ lU sXV ^š lZ]Œ U WXV D]v ÀU XV

s}oÇv]µlU

XV ,}šŒ U •XV

WZ}•‰Z}Œ • vš v

ŒÇ•Zv]l}ÀU 'XV ^šŒ}uÇo}U XV , oÌZÇv•lÇÇU /XV Z ‰Œ vU DXV

µo] v U XV d}ul À] ] v U XV s}ÌvÇ lU >XV 'Œ Ìµo À] ]µ•U :X sXU D]Æ]vP }(

Æ ]‰o Æ u]••]}v ]v ((] ] vš KŒP v]

o šŒ}oµu]v • vš

À] •X

• ‰‰o D š Œ

/vš Œ îìíñU ó ~î•U íîíõríîîñX òíX D] Z o À] ]µš U XV 'µŒ•lÇš U XV s}oÇv]µlU X zXV Z Œ‰ lU sX sXV ^]v]U 'XV ^š lZ]Œ U WX zXV 'Œ Ìµo À] ]µ•U :X sXU ^š Œr^Z ‰

Œ

Ì}o

Œ]À š]À • (}Œ ]o Ç Œ tZ]š KŒP v] >]PZšr u]šš]vP

]}

• }u ]v]vP

Æ ]‰o Æ •X dZ :}µŒv o }( WZÇ•] o Z u]•šŒÇ îìíîU ííò ~ïõ•U îìóòõr

u]••]}v (Œ}u }šZ Æ ]š}v• v îìóóôX

òîX W ŒlU zXr^XV ]U zXryXV t vPU XV :] vPU •XrYXV &µvPU DXr] }U >Xr^XU E}À} K>

•]Pv }( }Œ}vr

•

,}•š D š Œ] o• (}Œ ,]PZoÇ ((] ] vš oµ

• Á]šZ >}Á ((] ] v Ç Z}oorK((X

òòX ^ ]v}U zXV ^ •

^ ‰‰o]

D š Œ] o• ˜ /vš Œ(

U ,XV WµU zXr:XV

• h•]vP v ŒPÇ

D š Œ] o• îìíðU îò ~íì•U íòíîríòíòX

òóX > U :Xr,XV Z vPU ^Xr,XV z}}U ^Xr:XV ^Z]vU ,XV Z vPU :Xr,XV tµU Xr/XV t}vPU }Á Œ]À]vP s}oš P X

&µv š]}v o D š Œ] o• îìíñU îñ ~ï•U ïòírïòòX


À v

Page 29 of 30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


òôX dÇ vU zXr^XU KŒP v] o]PZšr u]šš]vPr ]} òõX ]& ^ o

]v }ŒP v] o]PZšr u]šš]vP ]}

•X :}µŒv o }( ‰‰o]

WZÇ•] • îììòU õõ ~î•U ìîðõìíX



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Table of Contents


Page 30 of 30

Highly Simplified Reddish Orange Phosphorescent Organic Light

Recommend Documents