Design Growth of MAPbI3 Single Crystal with (220) Facets Exposed

8 hours ago - MAPbI3 is deemed as the most prominent member in hybrid perovskites family because of its extremely optoelectronic properties. However, ...
1 downloads 20 Views 980KB Size
Subscriber access provided by UNIV OF NEW ENGLAND ARMIDALE

Letter 3

Design Growth of MAPbI Single Crystal with (220) Facets Exposed and its Superior Optoelectronic Properties Jianxu Ding, Lin Jing, Xiaohua Cheng, Ying Zhao, Songjie Du, Xiaoyuan Zhan, and Hongzhi Cui J. Phys. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.jpclett.7b03020 • Publication Date (Web): 22 Dec 2017 Downloaded from http://pubs.acs.org on December 24, 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.

The Journal of Physical Chemistry Letters 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 19 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

The Journal of Physical Chemistry Letters

Design Growth of MAPbI3 Single Crystal with (220) Facets Exposed and its Superior Optoelectronic Properties Jianxu Ding 1, *, Lin Jing 1, Xiaohua Cheng 1, Ying Zhao 1, Songjie Du 1, Xiaoyuan Zhan 1, Hongzhi Cui 1 1. College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China;

1

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 2 of 19

ABSTRACT: MAPbI3 is deemed as the most prominent member in hybrid perovskites family because of its extremely optoelectronic properties. However, some issues and puzzles are still in expection of their answers, such as stabilities, hysteresis, ferroelectricity, etc. To bridge the distinctions between MAPbI3 single crystal and thin films, large size single crystals are demanded. On the other hand, crystal structure anisotropy dependent optoelectronic properties is an inevitable topic. In this study, a series of large size MAPbI3 single crystals with (220) facets exposed were successfully grown, using high concentration solutions and large size seed crystals to match growth rates of (100) and (220) facets. The optoelectronic properties of photocurrents, responsivity, EQE, and detectivity clearly showed significant anisotropy of optoelectronic properties in MAPbI3 single crystal. According to ion migration theory, the anisotropy of optoelectronic properties was interpreted. We hope this result will be helpful to guide oriented growth MAPbI3 thin films. TOC Graphic

2

ACS Paragon Plus Environment

Page 3 of 19 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

The Journal of Physical Chemistry Letters

Benefiting from direct optical band gap,1 large optical absorption across the visible spectra band,2 long carrier lifetime and diffusion length,3 as well as solution process ability, perovskite semiconductors have attracted significant attentions in optoelectronic, electronic and photovoltaic related fields.4,5 By adjusting the cation and halide in perovskite structure ABX3, plenty of perovskite candidates are proposed, including hybrid perovskites and fully inorganic perovskites.6-8 Among them, methylammonium lead iodide (CH3NH3PbI3 or MAPbI3) is certainly the most popular and prominent member, which is widely applied in solar cells,9 lasers,10 light-emitting diodes,11 photo-detectors,12,13 field-effect transistors,14 etc. The easy processing of MAPbI3 from solutions provides various strategies to fabricate thin films, nano-wires, nano-sheets, and bulk single crystals,15-17 etc. Apparently, the morphologic variety of MAPbI3 offers numerous materials media to investigate the optoelectronic, electronic and photovoltaic properties. On the other hand, great optoelectronic and photovoltaic properties discrepancy between single crystal and polycrystalline counterpart brings confusions that which MAPbI3 morphology is more suitable for optoelectronic and photovoltaic applications. For example, the power conversion efficiency has rapidly climbed over 19.19 % for pure MAPbI3 thin film based solar cells,18 however, the power conversion efficiency of MAPbI3 single crystal based solar cells is still far behind. People are eagerly looking forward to realizing large scale MAPbI3 single crystal based solar cells, similar to single crystalline silicon solar cells. Before this, two important issues impede the way. One is controlling growth of large scale and excellent crystallinity thin MAPbI3 single crystal within hundreds nanometers, another is the optoelectronic and photovoltaic anisotropy. From the crystal engineering point view, the relationship between crystal 3

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 4 of 19

structure anisotropy and physical properties is should not be neglected. For hybrid perovskite materials, the influence of crystal structure anisotropy on optoelectronic and photovoltaic properties is recently raised concerns in oriented MAPbI3 and MAPbI3-xClx films,19,20 MAPbI3 and MAPbBr3 single crystals.21,22 However, till now, there are still lacking systematically investigations about anisotropy of optoelectronic properties for MAPbI3. It has been confirmed that hybrid perovskite is a mixed conductor,23 the migrations of electron-hole pairs generated upon photo-excitation, MA+ cation and I- anion under external bias voltage make contributions to optoelectronic properties. As we know that, the periodic arrangement of atoms in a single crystal results in various crystal facets whose atom density are different. Therefore, in MAPbI3 single crystal, the contribution of ion migrations to optoelectronic properties is facet-dependent. To fully dig out the anisotropy of optoelectronic properties and help controlling oriented growth of thin MAPbI3 single crystal, it is necessary to reveal the relationship between structure anisotropy and on anisotropy of optoelectronic properties in MAPbI3 single crystal. In this work, we firstly successfully grew large scale MAPbI3 single crystals, simultaneously exposed (100) and (220) facets by inverse temperature crystallization method (ITC). The excellent crystallinity of single crystal and large facet areas enabled us to fabricate facet based planar photo-detectors. By comparing the photocurrents, responsivity, external quantum efficiency and detectivity of (100) and (220) facet devices, the anisotropy of optoelectronic properties in MAPbI3 single crystal is revealed. Figure 1 displays a series of MAPbI3 single crystals with various facets exposed. Normally, (100) and (112) are the most easily exposed facets in MAPbI3 single crystal 4

ACS Paragon Plus Environment

Page 5 of 19 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

The Journal of Physical Chemistry Letters

growing from organic solvents. By carefully controlling the supersaturation of the growth solutions, large size (~19 mm) single crystal can be easily obtained from a 10 ml solution, as shown in Figure 1a. From the point view of crystallography, the equilibrium crystal shape are comprised by a trains of facets with larger the lattice distances (dhkl), whose growth rates are inverse to dhkl. In MAPbI3 single crystal, the similarity of d100 and d112 (4.4195 Å and 4.4535 Å) enforces their closer growth rates. However, equilibrium crystal shape will be changed once the relative growth rates are readjusted during crystal growth process. Taking an example of (220) facet, the lower d220 of 3.125 Å endows it a higher growth rate, which is hardly exposed. Therefore, to obtain such high index facets in MAPbI3 single crystal, the growth rate of (220) facet should be lowered and the growth rates or (100) and (112) facets should be increased. We chose large size single crystals (~4 mm) as seed crystals in high concentration solutions. The high concentration solution provides higher supersaturation, which is beneficial to increase the growth rate of (220) facet. On the other hand, the large scale seed crystals provide large area to accept growth units from solutions to guarantee lower growth rates. Under such circumstance, the growth rates for both (100) and (112) facets are controlled at low level. Using this method, a series of MAPbI3 single crystals with (220) facets exposed were grown, as shown in Figure 1(b-d). The (220) facets were determined according to the angles between (100) and (112) facets, which were elaborated by Bragg Equation:

  =

λ  

ℎ +  +    (1)

By precisely measuring the angles which are listed in Table 1, the corresponding facets are confirmed as (220) facets. Moreover, we can see that the (220) facets are

5

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 19

symmetrically exposed and exhibit as rectangles whose long sided are parallel or perpendicular to the scale line. The exposure of (220) facets provide excellent media for further investigate anisotropy of optoelectronic properties in MAPbI3 single crystal.

Figure 1 MAPbI3 single crystals with various crystal sizes and facets exposed: (a) normal single crystal with (100) and (112) exposed; (b-d) MAPbI3 single crystals with (220) facets exposed. Table 1 Angles between different crystal facets Facets

(100) vs (220)

(220) vs (112)

(112) vs (100)

Angles

135°

135.3°

120.17°

Figure 2a present the powder and (100) facet XRD patterns of MAPbI3. The powder XRD reveals the MAPbI3 was tetrahedral perovskite, with space group of I4/mcm. According to the (100) facet XRD, the trains of sharp peaks suggest excellent crystalline. The optical absorption and PL spectra of MAPbI3 single crystal is displayed in Figure 2b, and the absorption edge was located around 836 nm. The energy band gap Eg, was calculated to be 1.48 eV, narrower than the band gap 6

ACS Paragon Plus Environment

Page 7 of 19

values in polycrystalline films,24 which is attributed to excition absorption or indirect band-gap absorption.25,26 From the PL spectrum with a 404 nm excitation, the PL peak centered at 763 nm was detected, a red shift relative to previous results,27 which is attributed to the indirect band-gap absorption or Urbach band tail, similar to the results in the references.21,25 Further, the PL emission width was detected broad, ranging from 687 to 839 nm, implying that near-edge defects levels related to

20

30

40 2 Theta (°)

50

(440) 60

(600)

(404)

0.6

0.6

0.4 0.2 0.0

1/2

0.8

1.0 Abs. PL 0.8

(αhν)

Powder

Absorbance(a.u.)

(200) (200) (211) (202) (004) (114) (220) (310) (312) (321) (400) (314)

(002) (110)

10

b 1.0

(100) plane

(600)

(400)

a

1.48eV

836nm

1.0 1.2 1.4 1.6 1.8 2.0 hν(eV)

560

640 720 800 Wavelength (nm)

0.4

Normalized PL

surface states played roles in emission process.28

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

The Journal of Physical Chemistry Letters

0.2

880

0.0

Figure 2 (a) Powder and (100) facet XRD patterns of MAPbI3 single crystals, respectively; (b) The absorption and photoluminescence spectra of MAPbI3 single crystals. Using polished (100) and (220) facets, planar photo-detectors with Au interdigital electrodes were fabricated, such metal- semiconductor- metal (MSM) structure photo-detectors provide convenient devices to investigate the anisotropy of optoelectronic properties. Figure 3(a-b) illustrates the I-V curves under various illumination powers (0-15 mW) using a 405 nm laser diode for both (100) and (200) facets. The dark currents for (220) facet device are slightly higher than that acquired for (100) facet device at an applied voltage of 10 V, and the details are illustrated in Figure S1. The higher dark current on (220) facet implies a longer life of carrier 7

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 8 of 19

trapping.3,5,29 Under illuminations, the photo-currents increase with rise of illumination powers and bias voltages. As can be seen from Figure 3(a-b), for (100) facet device, the photocurrent under 5 mW illumination increases dramatically before 1 V, and the rising rate changes slowly over 1 V. Whereas this similar phenomena occurs over 2 V for (220) facet under the same illumination power. Moreover, the photocurrents of (220) facet device are higher than those at the same illumination powers, which suggests that (220) facet exhibit higher conductivities for carriers. As we know that, responsivities R, EQE and detectivity D are important factors to evaluate the photo-detectors devices, which depend sensitively on the applied voltages and incident laser power densities and can be obtained by the following formula:12

=

 

 = =

(1)

∗ ∗ 

(2)

 %

(3)

∗!"#$ 

where Ip and Id is photocurrents and dark current, respectively. P is illumination power density, S is the effective area, c is the light speed of and λ is the illumination wavelength. The R, EQE and D curves are displayed in Figure 3(c-d), from which we can see that the R, EQE and D are remarkably affected by illumination power and voltage. For (100) facet device, the highest values of R and EQE under 405 nm illumination and 10 V bias is 3.7 mA/W and 1.16 % respectively when the illumination power is 5 mW. In contrast to (100) facet device, the highest values of R and EQE for the (220) facet device is 19.5 mA/W and 6.55 % respectively. In addition, 8

ACS Paragon Plus Environment

Page 9 of 19

the D values increase with a rise of bias voltage, and reaches the maximum 5.5×1010 under 10 V for (100) facet device,whereas, it reaches to the maximum 1.0×1011 under 4.6 V and decreases with rise of voltage for (220) facet device. These results imply that the optoelectronic performance of MAPbI3 single crystal is greatly enhanced by (220) facet, which is more sensitive to illumination as photo-detector.

-5

8.0x10

1.0x10

-6

5.0x10

-5

4.0x10

0.0

c

4

2

5mW (100) 10mW 15mW

3

4 6 Voltage (V) 1.2

20

8

5mW (220) 10mW 15mW

EQE (%)

EQE (%) R (mA/W)

4 10

0.4 1

0

6

2 5

0

2 4 6 Voltage (V)

8

0

2

4 6 Voltage (V)

10

0.0 10

0

10

4.0x10

4 6 8 Voltage (V)

0 10

(220)

10

8.0x10

10

4.0x10

5mW 10mW 15mW

5mW 10mW 15mW

2.0x10

2

10

1.2x10

(100)

10

0

8

11

d 6.0x10

15 0.8

2

0.0

10

Detectivity (Jones)

0

Dark 5mW 10mW 15mW

-5

Current (A)

Current (A)

b

Dark 5mW 10mW 15mW

-5

1.5x10

Detectivity (Jones)

a

R (mA/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

The Journal of Physical Chemistry Letters

0.0 0

2

4

6

Voltage (V)

8

10

0

2

4

6

8

10

Voltage (V)

Figure 3(a-b) Dark and photocurrents curves of (100) and (220) facet photo-detectors respectively; (c) Responsivities and EQEs, and (d) detectivities of (100) and (220) facet photo-detectors respectively.

On the other hand, the photocurrent switch feather with illumination on/off at various applied voltages with illumination wavelength of 405 nm also clearly reflects the anisotropy of optoelectronic performance, which is depicted using six steady continues on/off time-dependent photocurrent circles in Figure 4(a-b). Despite of 9

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 19

the highest on/off ratio of 17 under 5 V bias for the (100) facet device is approximate to 15 for (220) facet device, the photocurrent changing tendency is quite different. As illustrated in Figure 4c, the photocurrent for (100) facet device maintains steady after it reaches the maximum, while it decreases rapidly for (220) facet device. This also suggests the anisotropy play crucial roles in optoelectronic properties in MAPbI3 single crystal. The discrepancy in optoelectronic property between (100) and (220) facets, is considered to be related with ionic conduction because MAPbI3 is a mixed conductor.23,30,31 Both theoretical calculations and experimental results have confirmed that I− is the most likely mobile ions in MAPbI3 along I--I- edge of the [PbI6] octahedron with a slightly curved pathway with an ultra-fast speed,23,32,33 and the migration of MA+ ions accumulates around the cathode region.34 These ion migrations easily occurred through point defects or local lattice distortions.33,35 From this point view, ion migrations are helpful to form novel optoelectronic devices. In MAPbI3 single crystal, the crystal structures of (100) and (220) facets are illustrated in Figure 4d. In (220) facet, the average density of I- ions is about 0.037 atoms /Å2, higher than that of (100) facet (0.026 atoms /Å2). The participation of I- ion migration in conduction brings higher photocurrent and responsivity, which is verified in I-V and responsivity curves. Moreover, the profiles of the [PbI6] octahedron are in zigzag arrangement for (220) facet, providing a I- migration depth vertical to (220) facet, which endows a curved I- ions migration channel, in agreement with the calculated results.23,32 According the references above, I− is the most mobile ion in MAPbI3, and it migrates along the I−-I− edge of the PbI6 octahedron. On the other hand, as shown in Figure 4(b-c), the photocurrent decay of (220) facet device is voltage-dependent, suggesting that the applied voltage plays roles in ion migrations. The migrations of I− 10

ACS Paragon Plus Environment

Page 11 of 19

and MA+ ions to anode and cathode under applied voltage can cause charge accumulation nearby the gold electrodes, and consequently, a reverse built-in electric potential is established and suppresses subsequent ion migrations to anode and cathode. Therefore, the photocurrents show decay tendency. On the other hand, the reverse built-in electric potential effect of (100) facet device is weaker than (220) facet device because of less ions participation in photocurrent, and the photocurrent for (100) facet device maintains steady after it reaches the maximum. Overall, our results show strong anisotropic optoelectronic properties caused by crystal orientations in MAPbI3 single crystal. We hope this result could evoke more attentions

about

anisotropic

optoelectronic

properties

for

perovskite

photo-detectors.

a

1V

2V

3V

4V

5V

b

-6

8.0x10

Current (A)

Current (A)

-6

6.0x10

-6

4.0x10

On -6

2.0x10

4.0x10

-6

3.0x10

-6

2.0x10

-6

1.0x10

-6

2V

3V

4V

5V

Off

0.0 20

1V

On

Off 40

60 Time (s)

c 7.8x10

80

100

120

0.0 20

40

60

80 Time (s)

100

120

140

Current (A)

-6

(100)

-6

7.5x10

-6

7.2x10

14

16

18 Time (s)

20

22

(220)

-6

Current (A)

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

The Journal of Physical Chemistry Letters

4.5x10

-6

4.2x10

-6

3.9x10128

130

132 134 Time (s)

136

138

Figure 4 (a-b) Six continues on-off circles under various applied voltages of (100) and (220) facet devices; (c) Detail current changing under 5 V of the devices; (d) 11

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 12 of 19

Comparison of surface structures on (100) and (220) facets of MAPbI3 single crystal.

According to the crystal morphology related to crystal structure of MAPbI3, and by adjusting the whole supersaturation of growth solution and decreasing the growth rates of (100) and (112) facets, large scale MAPbI3 single crystal with (220) facets exposed were successfully obtained from solutions. Such exposed (220) facets facilitate to investigate anisotropy of optoelectronic properties using planar MSM photo-detectors. The experimental results revealed greatly anisotropy of optoelectronic properties happened between (220) and (100) facets device in MAPbI3 single crystal, embodying in enhanced photocurrents, improved responsivity, EQE and detectivity for (220) facet device. The anisotropy of optoelectronic properties between (220) and (100) facets were interpreted in terms of surface structures and ion migrations.

EXPERIMENTAL SECTION CH3NH3PbI3 single crystals were grown from 1.5 M solutions by dissolving PbI2 (≥98%, Sinopharm chemical reagent) and CH3NH3I in γ-GBL (≥99%, Aladdin) at 60 °C with 1:1 mole ratio. After all salts were dissolved, the solutions were heated at 90 °C. It should be mentioned that the concentration of the solution is higher than that previously reported,27 which endow higher supersaturation. To avoid simultaneous crystals occur, and to realize (100), (112) and (220) facets growing at the same time, we chose large size seed crystals (~4 mm) and added into the 1.5 M yellow solutions at 90 °C. The synthesis of seed crystals as well as the detailed single crystal growth process were described in Supporting Information (Figure S2). After growing over 24 12

ACS Paragon Plus Environment

Page 13 of 19 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

The Journal of Physical Chemistry Letters

hours, large MAPbI3 single crystals with (220) facets exposed were successfully obtained. To avoid the influences of Schottky regions under electrodes and eliminate environmental contaminations and surface defects, both (100) and (220) facets of MAPbI3 single crystal were polished using dried silk without using any dispersing agents or polishing powders. After polishing, alloy hollow contact pattern masks were laid flat on the polished facets, and 150 µm width Au interdigitated electrodes were formed on the blank area of the hollowed mask during sputtering process. The photo of the device is illustrated in Figure S3 in the Supporting Information. Both powder and single crystal X-ray diffraction patterns of MAPbI3 were carried out on X-ray diffract meters (D/Max2500PC), with Cu KαI irradiation. UV-vis spectrum of MAPbI3 was collected on a UV-2550 spectrometer with an integrating sphere. The PL spectrum was obtained by employing a FLS-920 fluorescence spectroscopy (Edinburgh Instruments), using a 404 nm excitation wavelength. The electrical characteristics were carried out in air at room temperature using Keithly 2450 to collect photocurrents. To compare the anisotropy of optoelectronic properties in MAPbI3 single crystal, all measurements were carried out under the same excitation light sources, a semiconductor laser diodes (LD, 405 nm, 100 mW).

AUTHOR INFORMATION Corresponding Authors *

E-mail: [email protected] (J. X. Ding), Tel +86(532) 80691739

Notes 13

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 19

The authors declare no competing financial interest.

ACKNOWLEDGEMENTS This work was financially supported by Natural Science Foundation of Shandong Province (ZR2016EMQ10), National Natural Science Foundation of China (No. 51202131), SDUST Research Fund and Joint Innovative Center for Safe and Effective Mining Technology and Equipment of Coal Resources, Shandong Province (No. 2014JQJH102), Major Fundamental Research of Shandong Province, China (ZR2017ZB0318) and Distinguished Taishan Scholars in Climbing Plan (No. tspd20161006).

ASSOCIATED CONTENT Supporting Information The synthesized seed crystals, growth process of large MAPbI3 single crystal, the photo of the as fabricated planar photodetectors on (100) and (220) facets, the comparison of the dark currents can be found in the supporting information.

REFERENCES (1) Lee, M. M.; Teuscher, J.; Miyasaka, T.; Murakami, T. N.; Snaith, H. J. Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites. Science, 2012, 338, 643-647. (2) Xing, G.; Mathews, N.; Lim, S. S.; Yantara, N.; Liu, X., Sabba, D.; Grätzel, M.; Mhaisalkar, S.; Sum, T. C. Low-Temperature Solution-Processed Wavelength Tunable Perovskites for Lasing. Nat. Mater. 2014, 13, 476-480. (3) Shi, D.; Adinolfi, V.; Comin, R.; Yuan, M.; Alarousu, E.; Buin, A.; Chen, Y.; 14

ACS Paragon Plus Environment

Page 15 of 19 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

The Journal of Physical Chemistry Letters

Hoogland, S.; Rothenberger, A.; Katsiev, K.; et al. Low Trap-State Density and Long Carrier Diffusion in Organolead Trihalide Perovskite Single Crystals. Science, 2015, 347, 519-522. (4) Nie, W.; Tsai, H.; Asadpour, R.; Blancon, J. C.; Neukirch, A. J.; Gupta, G.; Crochet, J. J.; Chhowalla, M.; Tretiak, S.; Alam, M. A.; et al. High-Efficiency Solution-Processed Perovskite Solar Cells with Millimeter-Scale Grains. Science, 2015, 347, 522-525. (5) Huang, J.; Yuan, Y.; Shao, Y.; Yan, Y. Understanding the Physical Properties of Hybrid Perovskites for Photovoltaic Applications. Nat. Rev. Mater. 2017, 2, 17042. (6) Song, J.; Li, J.; Li, X.; Xu, L.; Dong, Y.; Zeng, H. Quantum Dot Light-Emitting Diodes Based on Inorganic Perovskite Cesium Lead Halides (CsPbX3). Adv. Mater. 2015, 27, 7162. (7) Jeon, N.; Noh, J.; Kim, Y.; Yang, W.; Ryu, S. Solvent Engineering for High-Performance Inorganic-Organic Hybrid Perovskite Solar Cells. Nat. Mater. 2014, 13, 897-903. (8) Lin, Q.; Armin, A.; Burn, P. L.; Meredith, P. Organohalide Perovskites for Solar Energy Conversion. Accounts Chem. Res. 2016, 49, 545-553. (9) Kim, H. D.; Ohkita, H.; Benten, H.; Ito, S. Photovoltaic Performance of Perovskite Solar Cells with Different Grain Sizes. Adv. Mater. 2016, 28, 917-922. (10) Zhu, H.; Fu, Y.; Meng, F.; Wu, X.; Gong, Z.; Ding, Q.; Gustafsson, M. V.; Trinh, M. T.; Jin, S.; Zhu, X. Y. Lead Halide Perovskite Nanowire Lasers with Low Lasing Thresholds and High Quality Factors. Nat. Mater. 2015, 14, 636. (11) Wong, A. B.; Lai, M.; Eaton, S. W.; Yu, Y.; Lin, E.; Dou, L.; Fu, A.; Yang, P. D. Growth 15

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 16 of 19

and Anion Exchange Conversion of CH3NH3PbX3 Nanorod Arrays for Light-Emitting Diodes. Nano Lett. 2015, 15, 5519.

(12)Lian, Z.; Yan, Q.; Lv, Q.; Wang, Y.; Liu, L.; Zhang, L.; Pan, S.; Li, Q.; Wang, L.; Sun, J. High-Performance Planar-Type Photodetector on (100) Facet of MAPbI3 Single Crystal. Sci. Rep. 2015, 5, 16563. (13) Yakunin, S.; Dirin, D. N.; Shynkarenko, Y.; Morad, V.; Cherniukh, I.; Nazarenko, O.; Kreil, D.; Nauser, T.; Kovalenko, M. V. Detection of Gamma Photons using Solution-Grown Single Crystals of Hybrid Lead Halide Perovskites. Nat. Photon. 2016, 10, 585-589. (14) Li, F.; Ma, C.; Wang, H.; Hu, W.; Yu, W.; Sheikh, A. D.; Wu, T. Ambipolar Solution-Processed Hybrid Perovskite Phototransistors. Nat. Comm. 2015, 6, 8238. (15) Meng, K., Gao, S.; Wu, L.; Wang, G.; Liu, X.; Chen, G.; Liu, Z.; Chen, G. Two-Dimensional Organic-Inorganic Hybrid Perovskite Photonic Films. Nano Lett. 2016, 16, 4166-4173. (16) Spina, M.; Bonvin, E.; Sienkiewicz, A.; Forró, L.; Horváth, E. Corrigendum: Controlled Growth of CH3NH3PbI3 Nanowires in Arrays of Open Nanofluidic Channels. Sci. Rep. 2016, 6, 19834. (17) Ding, J.; Zhao, Y.; Sun, Y.; Du, S.; Cui, H.; Jing, L.; Cheng, X.; Zuo, Z.; Zhan, X. Atomic Force Microscopy Investigation of a Step Generation and Bunching on the (100) Facet of a CH3NH3PbI3 Crystal Grown from γ-Butyrolactone. Cryst. Res. Tech. 2017, 52, 1700021. (18) Wu, Y.; Xie, F.; Chen, H.; Yang, X.; Su, H.; Cai, M.; Zhou, Z.; Noda, T.; Han, L. 16

ACS Paragon Plus Environment

Page 17 of 19 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

The Journal of Physical Chemistry Letters

Thermally Stable MAPbI3 Perovskite Solar Cells with Efficiency of 19.19 % and Area over 1 cm2 achieved by Additive Engineering. Adv. Mater. 2017, 29, 1701073. (19) Leblebici, S. Y.; Leppert, L.; Li, Y.; Reyeslillo, S. E.; Wickenburg, S.; Wong, E.; Lee, J.; Melli, M.; Ziegler, D.; Angell, D. K.; et al. Facet-Dependent Photovoltaic Efficiency Variations in Single Grains of Hybrid Halide Perovskite. Nat. Energy 2016, 1, 16093. (20) Cho, N.; Li, F.; Turedi, B.; Sinatra, L.; Sarmah, S. P.; Parida, M. R.; Saidaminov, M. I.; Murali, B.; Burlakov, V. M.; Goriely, A.; et al. Pure Crystal Orientation and Anisotropic Charge Transport in Large-area Hybrid Perovskite Films. Nat. Comm. 2016, 7, 13407. (21) Zuo, Z.; Ding, J.; Zhao, Y.; Du, S.; Li, Y.; Zhan, X.; Cui, H. Enhanced Optoelectronic Performance on the (110) Lattice Plane of an MAPbBr3 Single Crystal. J. Phys. Chem. Lett. 2017, 8, 684-689. (22) Ding, J. X.; Du, S. J.; Cheng, X. H.; Jing, L.; Zhao, Y.; Zuo, Z. Y.; Cui, H. Z.; Zhan, X. Y. Anisotropic Optoelectronic Performances on (112) and (100) Lattice Plane of Perovskite MAPbI3 Single Crystal. Mater. Chem. Phys. 2018, 204, 222-227. (23) Eames, C.; Frost, J. M.; Barnes, P. R.; O’regan, B. C.; Walsh, A.; Islam, M. S. Ionic Transport in Hybrid Lead Iodide Perovskite Solar Cells. Nat. Commun. 2015, 6, 7497. (24) Zulkifli, M. H., Bahtiar, A. Optical and Structural Properties of Perovskite Films Prepared with Two-Step Spin-Coating Method, Aip Conference Proceedings, Jatinangor, Indonesia, Sept 2-3, 2015; Joni, M.; Panatarani, J.; AIP Publishing: New York, 2016.

17

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 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 19

(25) Liu, Y.; Ren, X.; Zhang, J.; Yang, Z.; Yang, D.; Yu, F.; Sun, J.; Zhao, C.; Yao, Z.; Wang, B.; et al. 120 mm Single-Crystalline Perovskite and Wafers: Towards Viable Applications. Sci. China. Chem. 2017, 60, 1367-1376. (26) Chen, Z.; Dong, Q.; Liu, Y.; Bao, C.; Fang, Y.; Lin, Y.; Tang, S.; Wang, Q.; Xiao, X.; Bai, Y.; et al. Thin Single Crystal Perovskite Solar Cells to Harvest Below-Bandgap Light Absorption. Nat. Commun. 2017, 8, 1890. (27) Ding, J.; Du, S.; Zhao, Y.; Zhang, X.; Zuo, Z.; Cui, H.; Zhan, X.; Gu, Y.; Sun, H. High Quality Inorganic-Organic Perovskite CH3NH3PbI3 Single Crystals for Photo Detector Applications. J. Mater. Sci. 2017, 52, 276-284. (28) Azpiroz, J. M.; Mosconi, E.; Bisquert, J.; De Angelis, F. Defects Migration in Methylammonium Lead Iodide and their Role in Perovskite Solar Cells Operation. Energ. Environ. Sci. 2015, 8, 2118-2127. (29) Buin, A.; Pietsch, P.; Xu, J.; Voznyy, O.; Ip, A. H.; Comin, R.; Sargent, E. H. Materials Processing Routes to Trap-Free Halide Perovskites. Nano Lett. 2014, 14, 6281-6286. (30) Lin, Q.; Armin, A.; Nagiri, R. C. R.; Burn, P. L.; Meredith, P. Electro-Optics of Perovskite Solar Cells. Nat. Photon. 2014, 9, 106-112. (31) Tress, W.; Marinova, N.; Moehl, T.; Zakeeruddin, S.; Nazeeruddin, M. K.; Gratzel, M. Understanding the Rate-Dependent J-V Hysteresis, Slow Time Component, and Aging in CH3NH3PbI3 Perovskite Solar Cells: the Role of a Compensated Electric Field. Energy Environ. Sci. 2015, 8, 995-1004. (32) Yuan, Y.; Huang, J. Ion Migration in Organometal Trihalide Perovskite and Its 18

ACS Paragon Plus Environment

Page 19 of 19 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

The Journal of Physical Chemistry Letters

Impact on Photovoltaic Efficiency and Stability. Acc. Chem. Res. 2016, 49, 286-293. (33) Azpiroz, J. M.; Mosconi, E.; Bisquert, J.; De Angelis, F. Defects Migration in Methylammonium Lead Iodide and their Role in Perovskite Solar Cells Operation. Energy Environ. Sci. 2015, 8, 2118-2127. (34) Yuan, Y.; Chae, J.; Shao, Y.; Wang, Q.; Xiao, Z.; Centrone, A.; Huang, J. Photovoltaic Switching Mechanism in Lateral Structure Hybrid Perovskite Solar Cells. Adv. Energy Mater. 2015, 5, 1500615. (35) Choi, J. J.; Yang, X.; Norman, Z. M.; Billinge, S. J.; Owen, J. S. Structure of Methylammonium Lead Iodide within Mesoporous Titanium Dioxide: Active Material in High-Performance Perovskite Solar Cells. Nano Lett. 2014, 14, 127-133.

19

ACS Paragon Plus Environment