Controlled Aqueous Synthesis of 2D Hybrid Perovskites with Bright

Subscriber access provided by UNIV AUTONOMA DE COAHUILA UADEC

Surfaces, Interfaces, and Catalysis; Physical Properties of Nanomaterials and Materials

Controlled Aqueous Synthesis of 2D Hybrid Perovskites with Bright Room Temperature Long-Lived Luminescence Qi Zhang, Yujin Ji, Zhihui Chen, Daniele Vella, Xinyun Wang, Qing-Hua Xu, Youyong Li, and Goki Eda J. Phys. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.jpclett.9b00934 • Publication Date (Web): 15 May 2019 Downloaded from http://pubs.acs.org on May 15, 2019

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 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 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.

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 21 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

Controlled Aqueous Synthesis of 2D Hybrid Perovskites with Bright Room Temperature LongLived Luminescence Qi Zhang†#, Yujin Ji⊥#, Zhihui Chen§, Daniele Vella†,‡, Xinyun Wang†,‡, Qing-Hua Xu§, Youyong Li⊥, Goki Eda*†,‡,§

†Department

of Physics, National University of Singapore, 2 Science Drive 3, Singapore

117542

‡Graphene

Research Centre, National University of Singapore, 6 Science Drive 2,

Singapore 117546

§Department

of Chemistry, National University of Singapore, 3 Science Drive 3,

Singapore 117543

ACS Paragon Plus Environment

1

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

⊥Institute

Page 2 of 21

of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for

Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China

AUTHOR INFORMATION

Corresponding Author *[email protected]

ABSTRACT: Recently, some organic-inorganic hybrid perovskites (OIHPs) have been reported to exhibit strong sub-gap broadband luminescence. While the origin of such luminescence has been proposed by several groups, strategy to prepare OIHP with the desired sub-gap emission properties has remained elusive. Here, we report controlled synthesis of broadband-emitting single crystal two-dimensional (2D) OIHP with an average quantum yield of >80 %. We demonstrate that the intensity of broadband emission (BE) can be tuned by controlling the excess iodine ion concentration during the synthesis in hydroiodic acid (HI (a.q.)). We show that the emitters exhibit characteristics of localized defects such as limited mobility and saturation at high


2

Page 3 of 21 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


excitation power. Using density functional theory (DFT) calculations, we show that bond-state iodine interstitials are responsible for the observed long-lived luminescence. TOC GRAPHICS

KEYWORDS exciton lifetime, broadband photoluminescence, interstitial defect, selfassembly, solid state structure

Recently, some low-dimensional organic-inorganic hybrid perovskites (OIHPs) were reported to exhibit long-lived broadband sub-gap photoluminescence (PL) (Table S1).1-6 The emission is often peaked below the ground exciton resonance energy and is distinctly broad with a bandwidth of up to ~250 nm.7-14 The emission is significantly long-


3


Page 4 of 21

lived than free excitons, exhibiting lifetime approaching 1 µs and high quantum yield of >80 % in some cases.2,4 While the prospect for exploiting such luminescence centers for white light-emitting devices has generated great interest and have been widely studied in 0D and 1D perovskites, their origin and synthesis protocols in 2D perovskites still remain elusive, hampering further optimization of their emission characteristics.15-19 Until now, two mechanisms have been proposed to explain the origin of broadband emission (BE). Dohner et al.8 studied the effect of chemical structure and proposed that exciton-induced strong deformation of the lattice results in the formation of transient mid-gap states that are widely distributed over the system’s electronic spectrum. Other groups have attributed BE to crystal defects serving as color centers. Booker et al.1 observed that spin-coated films exhibit BE while single crystal samples did not, and proposed that iodine interstitial defects are responsible. However, other reports show that spin-coating does not consistently yield broadband emitting materials, questioning the role of defects.20-24 In this article, we report controlled synthesis of broadband-emitting single crystal OIHP by crystallization in aqueous hydroiodic acid (HI (a.q.)). We demonstrate that the intensity of BE can be correlated with the excess


4

Page 5 of 21 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


halogen during the synthesis, and show that the emission originates from localized states due to bond-state iodide.

Figure 1a schematically illustrates the synthesis OIHP crystals in excess iodine ions using aqueous HI as the solvent. For the synthesis of (C6H5C2H4NH3)2PbI4 (PEPI) crystals, stoichiometric amount of ammonium salt (C6H5C2H4NH3I) and lead iodide (PbI2) were dissolved in 100 ºC HI (a.q.) until near saturation. Perovskite crystals were grown by slowly cooling down the solution to room temperature. These crystals are labeled XI-PEPI, where X represents the molar fraction of excess iodine during synthesis. X=0.157 denotes the case of synthesis by as-received HI solution (57 wt%). While the exact chemical reaction route is unclear, we conjecture that I- is oxidized during synthesis due to the absence of a reducing agent such as H3PO2. Control crystals were prepared in absence of excess iodine ions using N,N-dimethylformamide (DMF) as the solvent and they are labeled as 0I-PEPI.25 Figure 1b and c show optical micrograph and corresponding fluorescence image of typical as-synthesized crystals. Surprisingly, the crystal prepared in HI solution exhibits yellowish emission which is


5


Page 6 of 21

distinctly different from the green emission of typical n=1 PEPI crystals. The absorbance (Abs) spectra of the two crystals show similar absorption peak at 520 nm, which is expected for n=1 PEPI (Figure 1d and e). On the other hand, 0.157I-PEPI exhibits a broadband peak centered at ~700 nm (FWHM ~340 meV) on top of the less intense 1s exciton emission at 530 nm, which is the sole feature of 0I-PEPI emission spectrum. It should be noted that the BE was not observed from spin-coated polycrystalline 0I-PEPI, which indicates that its origin is strictly associated with excess iodine rather than grain boundaries (Figure S1). The PL quantum yield of the crystals was found to be ~83 % for 0.157I-PEPI (Figure S2), which is among the highest room temperature values for 2D perovskites reported to date, and significantly exceeding ~30 % for 0I-PEPI.26,27 Figure 1f and g show time-resolved PL measurements revealing that the BE is three orders of magnitude more long-lived (~150 ns) compared to the 1s exciton emission (~150 ps). The emission spectral features and the lifetime are similar to those reported by Booker et al.,1 suggesting that they share the same origin. While the unusually long emission lifetime in 0.157I-PEPI suggests the possible role of triplet states as discussed by


6

Page 7 of 21 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


Younts et al.,28 we found no evidence of triplet states in energy transfer experiments using perylene (see Supporting Information).

Figure 1. (a) Schematic of XI-PEPI single crystal synthesis. (b, c) Optical micrograph and corresponding fluorescence images under blue (450-480 nm) excitation for (b)


7


Page 8 of 21

0.157I-PEPI and (c) 0I-PEPI crystal. Scale bars for (b) are 50µm, for (c) are 10µm. (d, e) UV-Vis Abs and PL spectra of (d) 0I-PEPI flakes and (e) 0.157I-PEPI flakes. (f) Spectrally resolved PL lifetime of 0.157I-PEPI. (g) Time-resolved PL of the BE at 700nm. Inset shows the lifetime of 1s exciton emission of 0I- and 0.157I-PEPI flakes at 524nm.

We studied a range of OIHP crystals using several different organic precursors including hexylamine (C6), octylamine (C8), dodecylamine (C12), and hexadecylamine (C16) and the same behaviors were observed in all samples. This implies that the organic moiety is not responsible for the emergence of BE (Figure S3). Based on powder X-ray diffraction (PXRD) and Raman spectroscopy (see Figure S4 and S5) analyses, 0I-PEPI and 0.157I-PEPI crystals consist of a single phase, and are virtually indistinguishable. Thus, the emission cannot be attributed to different phases of the material.

Figure 2a shows the excitation power dependence of room temperature PL intensity for the 1s exciton and BE. The power exponent for the 1s emission is 0.97,


8

Page 9 of 21 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


which is consistent with free exciton picture.29 On the other hand, the power exponent of the BE is 0.76, which is indicative of defect-mediated localized exciton emission. To verify this, we conducted steady-state exciton diffusion imaging to estimate the mobility of the luminescent states.30,31 Figure 2b shows the spatial distribution of 1s exciton and BE and their intensity profile, which is fitted according to the steady-state onedimensional diffusion equation, dn/dt=0=G+D(d2n/d2x)-kn, where G is a Gaussian generation function, D is diffusion coefficient, k is exciton recombination rate and n is exciton density. While the BE appears to diffuse over large distances, considering their long lifetime, the diffusion coefficient of broadband emitters is 100 times smaller than that of 1s excitons. The small diffusion coefficient is an indication of strong localization and deep trap potential, consistent with the defect-mediated emission as discussed above. The photoluminescence excitation spectrum of BE is found to follow absorption spectrum of the material, suggesting that the localized states are electronically coupled to the bulk exciton states (Figure S6).


9


Page 10 of 21

Figure 2. (a) Excitation power dependence of PL of 0.157I-PEPI monitoring at 1s excitonic and BE, respectively. (b) Spatial distribution of excitation laser spot, 1s excitonic and BE respectively, along horizontal direction as indicated by white dash line. Gaussian function was used to fit the curves. Inset shows raw data of PL imaging and the dash circles indicate diffusion regions correspondingly. The calculated diffusion coefficient are D1s= 7.35*10-5 m2s-1 and DBE= 5.65*10-7 m2s-1.

Figure 3a-d show the optical micrograph and corresponding fluorescence images of PEPI crystals prepared with different excess iodine concentrations. With increasing X, the crystals exhibit diminishing area with green 1s exciton emission. BE is nonuniform at intermediate concentrations but becomes uniform at high concentrations


10

Page 11 of 21 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


(Figure 3 and S7). The average spectra show increasing ratio between broadband and 1s exciton emission with increasing iodine ion concentration (Figure 3e). The average intensity ratio IBE/I1s exhibits rapid increase with the excess iodine concentration, indicating that the defect is associated with incorporated iodine (Figure 3f).

Figure 3. Optical micrograph and fluorescence images of XI-PEPI flakes synthesized with excess iodine concentration at (a) 0.032I, (b) 0.073I, (c) 0.113I and (d) 0.157I,


11


Page 12 of 21

respectively. (e) Typical PL spectra of XI-PEPI obtained at different excess iodine concentrations. (f) Statistics and average value of PL intensity ratio IBE/I1s of XI-PEPI obtained at different excess iodine concentrations. Dashed line is a guide to the eye. Due to the non-uniformity of BE, we conducted multiple measurements on individual crystals. Each batch contains ten measurement data points. Scale bars for (a)-(c) are 50µm and for (d) is 100µm.

We conducted DFT calculations to determine the formation energy of various types of defects and their impact on the electronic structure (see details in Supporting Information and Figure S8). We studied various types of defects including vacancies (VI and VPb), free and bond-state iodine interstitials (II1 and II2), Frenkel and antisite defects. VI has low formation energy in I-poor condition whereas II defects preferentially form in iodine-rich condition (the formation energies are summarized in Table S2), which corresponds well with the results reported by Liu and co-workers.32

Figure 4 shows the structure and projected density of states of pristine PEPI and PEPI with II1, II2 and VPb. The pristine PEPI has a band gap of 2.19 eV. Free-state


12

Page 13 of 21 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


interstitial has little influence on the electronic structure whereas the bond-state interstitial introduces a deep level mid-gap state. VPb is found to increase the fundamental gap rather than introduce mid-gap states. While iodine Frenkel defects and antisite defects were found to introduce similar deep levels (Figure S9), they are significantly less likely to form due to high formation energies. Thus, given that sub-gap BE is observed only from crystals that were prepared in iodine-rich condition, we attribute the emission to bond-state iodine interstitials.

Figure 4. Lattice structures and projected density of states of: (a, e) pristine 0I-PEPI; (b, f) free-state interstitial iodide defect (II1); (c, g) bond-state interstitial iodide defect (II2)


13


Page 14 of 21

and (d, h) lead vacancy (VPb). Red dash circles indicate the positons of corresponding defects. Iodine atoms exclude interstitial defects are not shown for clarity.

In summary, we have developed a facile recipe to synthesize 2D OIHP with bright and long-lived sub-band-gap PL with room temperature quantum yield as high as 83 %. We demonstrate that the excess iodine during synthesis determines the emergence of these localized luminescent states. DFT calculations further show that excess iodine favors the formation of iodine interstitials which mainly contribute to the sub-band-gap states. This study reveals the origin and properties of sub-band-gap emission in 2D OIHP, which makes 2D OIHP promising for white light emitting devices and highly efficient phosphor.

ASSOCIATED CONTENT

Supporting Information.


14

Page 15 of 21 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 Supporting Information is available free of charge on the ACS Publications website at DOI:

Details of material synthesis, details of optical spectroscopy setup, details of computational methods, quantum yield summary, UV-vis absorption spectra, reflectance and transmittance spectra, low temperature PL spectra, XRD analysis, Raman spectra, photoluminescence excitation spectra, PL mapping, defects formation energies, calculated projected density of state of defects, energy dispersive spectroscopy (PDF)

AUTHOR INFORMATION

Corresponding Author *E-mail:

[email protected]

Notes

Q. Z. and Y. J. contributed equally to the work. The authors declare no competing financial interests.

ACKNOWLEDGMENT


15


Page 16 of 21

This work was supported by MOE under AcRF Tier 2 (MOE2015-T2-2-123). The authors also acknowledge the support from the National Research Foundation, Prime Minister’s Office, Singapore, under its NRF research fellowship (NRF-NRFF2011-02) and Medium Sized Centre Program.

REFERENCES (1) Booker, E. P.; Thomas, T. H.; Quarti, C.; Stanton, M. R.; Dashwood, C. D.; Gillett, A. J.; Richter, J. M.; Pearson, A. J.; Davis, N.; Sirringhaus, H.; Price, M. B.; Greenham, N. C.; Beljonne, D.; Dutton, S. E.; Deschler, F. Formation of long-lived color centers for broadband visible light emission in low-dimensional layered perovskites. J. Am. Chem.

Soc. 2017, 139, (51), 18632-18639. (2) Mao, L.; Wu, Y.; Stoumpos, C. C.; Wasielewski, M. R.; Kanatzidis, M. G. Whitelight emission and structural distortion in new corrugated two-dimensional lead bromide perovskites. J. Am. Chem. Soc. 2017, 139 (14), 5210–5215. (3) Yangui, A.; Garrot, D.; Lauret, J. S.; Lusson, A.; Bouchez, G.; Deleporte, E.; Pillet, S.; Bendeif, E. E.; Castro, M.; Triki, S.; Abid, Y.; Boukheddaden, K. Optical investigation of broadband white-light emission in self-assembled organic–inorganic perovskite (C6H11NH3)2PbBr4. J. Phys. Chem. C 2015, 119, (41), 23638-23647.


16

Page 17 of 21 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


(4) Zhou, C.; Tian, Y.; Yuan, Z.; Lin, H.; Chen, B.; Clark, R.; Dilbeck, T.; Zhou, Y.; Hurley, J.; Neu, J.; Besara, T.; Siegrist, T.; Djurovich, P.; Ma, B. Highly efficient broadband yellow phosphor based on zero-dimensional tin mixed-halide perovskite.

ACS Appl. Mater. Interfaces 2017, 9, (51), 44579-44583. (5) Lin, H.; Zhou, C.; Tian, Y.; Besara, T.; Neu, J.; Siegrist, T.; Zhou, Y.; Bullock, J.; Schanze, K. S.; Ming, W. Bulk assembly of organic metal halide nanotubes. Chem. Sci. 2017, 8, (12), 8400-8404. (6) Yuan, Z.; Zhou, C.; Tian, Y.; Shu, Y.; Messier, J.; Wang, J. C.; Van De Burgt, L. J.; Kountouriotis, K.; Xin, Y.; Holt, E. One-dimensional organic lead halide perovskites with efficient bluish white-light emission. Nat. Commun. 2017, 8, 14051. (7) Cortecchia, D.; Neutzner, S.; Srimath Kandada, A. R.; Mosconi, E.; Meggiolaro, D.; De Angelis, F.; Soci, C.; Petrozza, A. Broadband emission in two-dimensional hybrid perovskites: the role of structural deformation. J. Am. Chem. Soc. 2017, 139, (1), 39-42. (8) Dohner, E. R.; Hoke, E. T.; Karunadasa, H. I. Self-assembly of broadband whitelight emitters. J. Am. Chem. Soc. 2014, 136, (5), 1718-21. (9) Hu, T.; Smith, M. D.; Dohner, E. R.; Sher, M. J.; Wu, X.; Trinh, M. T.; Fisher, A.; Corbett, J.; Zhu, X. Y.; Karunadasa, H. I.; Lindenberg, A. M. Mechanism for broadband white-light emission from two-dimensional (110) hybrid perovskites. J. Phys. Chem.

Lett. 2016, 7, (12), 2258-63.


17


Page 18 of 21

(10) Peng, Y.; Yao, Y.; Li, L.; Wu, Z.; Wang, S.; Luo, J. White-light emission in a chiral one-dimensional organic–inorganic hybrid perovskite. J. Mater. Chem. C 2018, 6, (22), 6033-6037. (11) Smith, M. D.; Karunadasa, H. I. White-light emission from layered halide perovskites. Acc. Chem. Res. 2018, 51, (3), 619-627. (12) Thirumal, K.; Chong, W. K.; Xie, W.; Ganguly, R.; Muduli, S. K.; Sherburne, M.; Asta, M.; Mhaisalkar, S.; Sum, T. C.; Soo, H. S.; Mathews, N. Morphology-independent stable white-light emission from self-assembled two-dimensional perovskites driven by strong exciton–phonon coupling to the organic framework. Chem. Mater. 2017, 29, (9), 3947-3953. (13) Wang, S.; Yao, Y.; Kong, J.; Zhao, S.; Sun, Z.; Wu, Z.; Li, L.; Luo, J. Highly efficient white-light emission in a polar two-dimensional hybrid perovskite. Chem.

Commun. (Camb) 2018, 54, (32), 4053-4056. (14) Wu, G.; Zhou, C.; Ming, W.; Han, D.; Chen, S.; Yang, D.; Besara, T.; Neu, J.; Siegrist, T.; Du, M.-H.; Ma, B.; Dong, A. A One-dimensional organic lead chloride hybrid with excitation-dependent broadband emissions. ACS Energy Lett. 2018, 3, (6), 14431449. (15) C. Zhou,; H. Lin,; H. Shi,; Y. Tian,; C. Pak,; M. Shatruk,; Y. Zhou,; P. Djurovich,; M. H. Du,; B. Ma A zero‐dimensional organic seesaw‐shaped tin bromide with highly


18

Page 19 of 21 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


efficient strongly stokes‐shifted deep‐red emission. Angew. Chem. Int. Ed. 2018, 57, (4), 1021-1024. (16) D. Han,; H. Shi,; W. Ming,; C. Zhou,; B. Ma,; B. Saparov,; Y.-Z. Ma,; S. Chen,; M.-H. Du Unraveling luminescence mechanisms in zero-dimensional halide perovskites.

J. Mater. Chem. C 2018, 6, (24), 6398-6405. (17) C. Zhou,; H. Lin,; Y. Tian,; Z. Yuan,; R. Clark,; B. Chen,; L. J. van de Burgt,; J. C. Wang,; Y. Zhou,; K. Hanson Luminescent zero-dimensional organic metal halide hybrids with near-unity quantum efficiency. Chem. Sci. 2018, 9, (3), 586-593. (18) H. Lin,; C. Zhou,; Y. Tian,; T. Siegrist,; B. Ma Low-dimensional organometal halide perovskites. ACS Energy Lett. 2017, 3, (1), 54-62. (19) C. Zhou,; H. Lin,; Q. He,; L. Xu,; M. Worku,; M. Chaaban,; S. Lee,; X. Shi,; M.-H. Du,; B. Ma Low dimensional metal halide perovskites and hybrids. Mater. Sci. Eng. R-

Rep 2019, 137, 38-65. (20) Dammak, T.; Koubaa, M.; Boukheddaden, K.; Bougzhala, H.; Mlayah, A.; Abid, Y. Two-dimensional excitons and photoluminescence properties of the organic/inorganic (4-FC6H4C2H4NH3)2[PbI4] nanomaterial. J. Phys. Chem. C 2009, 113, (44), 1930519309.


19


Page 20 of 21

(21) Gauthron, K.; Lauret, J.; Doyennette, L.; Lanty, G.; Al Choueiry, A.; Zhang, S.; Brehier, A.; Largeau, L.; Mauguin, O.; Bloch, J. Optical spectroscopy of two-dimensional layered (C6H5C2H4-NH3)2-PbI4 perovskite. Opt. Express 2010, 18, (6), 5912-5919. (22) Kitazawa, N.; Aono, M.; Watanabe, Y. Synthesis and luminescence properties of lead-halide based organic–inorganic layered perovskite compounds (CnH2n+1NH3)2PbI4 (n=4, 5, 7, 8 and 9). J. Phys. Chem. Solids 2011, 72, (12), 1467-1471. (23) Kitazawa, N.; Aono, M.; Watanabe, Y. Temperature-dependent time-resolved photoluminescence of (C6H5C2H4NH3)2PbX4 (X=Br and I). Mater. Chem. Phys. 2012,

134, (2-3), 875-880. (24) Zhang, S.; Lanty, G.; Lauret, J.-S.; Deleporte, E.; Audebert, P.; Galmiche, L. Synthesis and optical properties of novel organic–inorganic hybrid nanolayer structure semiconductors. Acta Mater. 2009, 57, (11), 3301-3309. (25) Lédée, F.; Trippé-Allard, G.; Diab, H.; Audebert, P.; Garrot, D.; Lauret, J.-S.; Deleporte, E. Fast growth of monocrystalline thin films of 2D layered hybrid perovskite.

CrystEngComm 2017, 19, (19), 2598-2602. (26) Yang, S.; Niu, W.; Wang, A. L.; Fan, Z.; Chen, B.; Tan, C.; Lu, Q.; Zhang, H. Ultrathin two-dimensional organic-inorganic hybrid perovskite nanosheets with bright, tunable photoluminescence and high stability. Angew. Chem. Int. Ed. 2017, 56, (15), 4252-4255.


20

Page 21 of 21 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


(27) Zhang, Q.; Chu, L.; Zhou, F.; Ji, W.; Eda, G. Excitonic properties of chemically synthesized 2D organic-inorganic hybrid perovskite nanosheets. Adv. Mater. 2018, 30, (18), 1704055. (28) Younts, R.; Duan, H. S.; Gautam, B.; Saparov, B.; Liu, J.; Mongin, C.; Castellano, F. N.; Mitzi, D. B.; Gundogdu, K. Efficient generation of long-lived triplet excitons in 2D hybrid perovskite. Adv. Mater. 2017, 29, (9). (29) Schmidt, T.; Lischka, K.; Zulehner, W. Excitation-power dependence of the nearband-edge photoluminescence of semiconductors. Phys. Rev. B: Condens. Matter

Mater. Phys. 1992, 45, (16), 8989-8994. (30) Irkhin, P.; Biaggio, I. Direct imaging of anisotropic exciton diffusion and triplet diffusion length in rubrene single crystals. Phys. Rev. Lett. 2011, 107, (1), 017402. (31) Kato, T.; Kaneko, T. Transport dynamics of neutral excitons and trions in monolayer WS2. ACS Nano 2016, 10, (10), 9687-9694. (32) Liu, Y.; Xiao, H.; Goddard III, W. A. Two-dimensional halide perovskites: tuning electronic activities of defects. Nano Lett. 2016, 16, (5), 3335-3340.


21

Controlled Aqueous Synthesis of 2D Hybrid Perovskites with Bright

Recommend Documents