Phase Stability and Electronic Structure of Prospective Sb-Based

Subscriber access provided by UNIVERSITY OF THE SUNSHINE COAST

Energy Conversion and Storage; Plasmonics and Optoelectronics

Phase Stability and Electronic Structure of Prospective Sbbased Mixed Sulfide and Iodide 3D Perovskite (CHNH)SbSI 3

3

2

Tianyang Li, Xiaoming Wang, Yanfa Yan, and David B. Mitzi J. Phys. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.jpclett.8b01641 • Publication Date (Web): 26 Jun 2018 Downloaded from http://pubs.acs.org on June 26, 2018

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 17 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

Phase Stability and Electronic Structure of Prospective Sb-based Mixed Sulfide and Iodide 3D Perovskite (CH3NH3)SbSI2 Tianyang Li1, #, Xiaoming Wang2, #, Yanfa Yan2, * and David B. Mitzi1, * 1

Department of Mechanical Engineering and Materials Science, and Department of Chemistry,

Duke University, Durham, North Carolina 27708, United States 2

Department of Physics and Astronomy and Wright Center for Photovoltaics Innovation and

Commercialization, The University of Toledo, Toledo, Ohio 43606, United States AUTHOR INFORMATION Corresponding Author *[email protected] *[email protected]

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

Page 2 of 17

ABSTRACT

Lead-free antimony based mixed sulfide and iodide perovskite phases have recently been reported to be synthesized experimentally and to exhibit reasonable photovoltaic performance. Through a combination of experimental validation and computational analysis, we show no evidence of the formation of the mixed sulfide and iodide perovskite phase, MASbSI2 (MA=CH3NH3+), and instead that the main products are a mixture of the binary and ternary compounds (Sb2S3 and MA3Sb2I9). Density functional theory calculations also indicate that such a mixed sulfide and iodide perovskite phase should be thermodynamically less stable compared to binary/ternary anion-segregated secondary phases and less likely to be synthesized under equilibrium conditions. Additionally, band structure calculations show that this mixed sulfide and iodide phase, if possible to synthesize (e.g., under non-equilibrium conditions), should have a suitable direct band gap for photovoltaic application.

TOC GRAPHICS


2

Page 3 of 17 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 past few years have witnessed the rapid increase in power conversion efficiency (PCE) of lead halide perovskite based solar cells.1-6 The active absorber material typically has a general formula of ABX3, where A is an organic (e.g. methylammonium (MA)) or inorganic (e.g. Cs+) cation, B is lead and X is the halogen. However, one of the major concerns that hinders the commercialization of this technology is the toxicity of lead. Extensive efforts have been devoted to discovering new perovskite-type compounds that contain nontoxic or low-toxicity elements,711

among which Sb3+/Bi3+ are of particular interest as replacements for Pb2+ because they

preserve the lone-pair electrons that are beneficial for the superior photovoltaic performance in the lead halide perovskites.12,

13

However, the resulting Sb- or Bi-based A3B2X9 compounds

typically exhibit low structural dimensionality, larger band gap energy and overall poor photovoltaic performances.12, 14-18 Recently, a Sb-based three-dimensional (3D) perovskite phase has been reported, stabilized by introducing sulfur into the structure and evidently leading to a MASbSI2 mixed sulfide and iodide perovskite (Figure 1a) with a band gap energy of around 2 eV.19 The rationale behind the stability of such a phase is that the tolerance factor calculated based on the ionic radii of MA+, Sb3+, S2- and I- is 0.99, which is close to that for the ideal cubic perovskite structure. Lacking an experimental crystal structure determined from X-ray diffraction, density functional theory (DFT) was used to relax the proposed perovskite structure, leading to the conclusion that the sulfur atoms reside at the axial positions in a highly distorted octahedral geometry, with Sb-S bond lengths of ~ 3.6Å and ~2.27Å. It should be noted that these values do not fall into the generally accepted range of Sb-S bond lengths. In fact, through a search in the Inorganic Crystal Structure Database (ICSD), the Sb-S bond lengths of Sb3+-based mixed sulfide and halide compounds range from approximately 2.4 Å to 3.3 Å, and no reliable results can be found for


3


Page 4 of 17

binary, ternary and quaternary Sb3+-based compounds that have Sb-S bond lengths smaller than 2.3 Å or larger than 3.5Å. It has also previously been predicted from DFT calculations that the Cs-based mixed sulfide and halide perovskites are not stable against decomposition into binary or ternary phases (Figure 1b),20 bringing into question whether the methylammonium analogs would behave differently.

Figure 1. (a) Proposed structure of MASbSI2 from DFT relaxation and (b) crystal structure of Cs3Sb2I9 as a representative member of the A3Sb2I9 family. Here, we present a combination of experimental study using solid state synthesis methods, similar to that from the previous report,19 and DFT calculations to show that such a Sb-based mixed sulfide and iodide perovskite phase is not expected to be stable; rather, the ternary MA3Sb2I9 phase is the more stable phase and is expected to dominate the reaction product when combining MAI and SbSI. It has been proposed that by reacting antimony sulfur iodide (SbSI) with methylammonium iodide (MAI) in a solid mixture, it is possible to synthesize the mixed sulfide and iodide perovskite MASbSI2 (Figure 1a), following the route of Equation 119: SbSI MAI ⟶ MASbSI Equation 1


4

Page 5 of 17 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


To validate this equation, we carried out the solid-state reaction by preparing a pellet with 1:1 molar ratio mixture of SbSI and MAI and annealing it under nitrogen atmosphere at different temperatures closely resembling those used in the earlier report.19 Varying the reaction conditions does not change the product significantly, as determined from the powder X-ray diffraction (XRD) patterns (Figure S1). The reaction progresses slowly (over a period of weeks). Annealing in an open container (for example an open vial) results in the evaporation of MAI and diminished MAI peaks in the XRD pattern, while the rest of the pattern remains similar to that from a sealed container at the same temperature. Additionally, such reaction at 150 °C in an open container leads to a product having a similar XRD pattern as that of the MASbSI2 sample prepared by the same method in ref. 19 (Figure S2), with almost all the peaks matched in position (the pattern from ref. 19 has broader peaks, evidently due to reduced crystallinity). In comparing both patterns (that from Ref. 19 and from the current 150 °C open container reaction), both patterns appear to more closely match the XRD pattern of the MA3Sb2I9 phase, with some peak intensity variations, rather than that of the simulated MASbSI2 structure. Further examination of the solid using optical microscopy (Figure S3) clearly shows that the product contains two distinctive phases: a red phase and a dark grey phase. This analysis suggests that one of the products of Equation 1 may be MA3Sb2I9 instead of MASbSI2 and that Equation 1 may not accurately reflect the processes occurring during and the resulting majority phases present after the solid-state reaction. To unambiguously identify the product phases of the solid-state reaction, we annealed the pellet in a sealed autoclave at 160 °C, over a 4-week period (aiming for better crystallinity using the higher temperature), and monitored the reaction progression via the color of the reaction product,


5


Page 6 of 17

XRD and diffuse reflectance spectroscopy. The initial powder mixture and pellet containing unreacted SbSI and MAI appear to be red and the solid-state reaction progresses slowly due to the slow diffusion of ions, even at the higher temperature. The color of the solid product becomes darker over time and turns dark gray after four weeks of reaction. The change in color is associated with the shift of absorption onset in the diffuse reflection spectra in Figure 2a. The unreacted mixture of SbSI and MAI has an onset around 640 nm, close to the absorption onset of SbSI (band gap around 1.9 eV)

21, 22

. After two weeks of reaction, an additional onset appears

around 750 nm and becomes much more pronounced with longer reaction time. This indicates there is an additional phase emerging with band gap around 1.7 eV (Figure S4). The original lower wavelength onset redshifts by 20-30 nm and still has a significant contribution to the absorption spectrum. Interestingly, this onset coincides with the absorption edge of MA3Sb2I9, as shown in Figure 2a. The change in absorption spectra during the reaction suggests that, instead of forming a single phase of MASbSI2 with a band gap of ~2.0 eV,19 there seems to be two distinct products with different band gap energies in the reaction mixture.


6

Page 7 of 17 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 2. (a) absorption spectra of MA3Sb2I9 and the SbSI + MAI reaction mixture before and during of the reaction at 160 °C, (b) comparison of measured XRD pattern of solid-state reaction


7


Page 8 of 17

product mixture and the simulated XRD pattern of MASbSI2 based on the DFT-relaxed structure, and (c) Pawley profile fitting of the XRD pattern of the 160 °C solid-state reaction product to a mixture of MAI, MA3Sb2I9 and Sb2S3. Peaks labeled by black asterisk are from MAI, and peaks labeled by green asterisk are from Sb2S3, black pattern is from MA3Sb2I9 synthesized by solution methods, green stick pattern is from the Sb2S3 standard (PDF#42-1393). To identify the phases within the reaction mixture, XRD patterns were taken during different durations of the reaction (Figure S5). The XRD peaks (around 10°, 20° and 24.6°) of MAI remain dominant until the reaction completion (since, in this case, the reaction is performed in a sealed ampule) and the peaks (two peaks at ~21° and two peaks at ~30°) from the other reactant, SbSI, also remain visible after two weeks of reaction. The reaction goes to completion after four weeks as no further noticeable change can be observed for longer reaction time. The measured XRD pattern is compared with the simulated pattern of the DFT-relaxed MASbSI2 structure (Figure 2b; see discussion of DFT theory approach below and in the Supplemental Information). While some of the peaks do overlap or are slightly offset with respect to the proposed phase, it is clear that many other peaks cannot be accounted for and they cannot be indexed to a single phase. A Pawley profile fitting was attempted using the as-mentioned MASbSI2 phase; however, it did not result in reasonable fitting parameters (i. e., Rp > 0.15 and Rwp > 0.20 resulted), with many peaks unfitted and an unacceptably large difference curve. After considering other possible products, at least two known phases from the mixture, MA3Sb2I9 and Sb2S3 (peaks of Sb2S3 that are distinct from other phases are marked by green asterisks in Figure 2c), can readily be identified. Additionally, Sb2S3 (dark grey) has a band gap around 1.7 eV23 and MA3Sb2I9 (red) has a band gap around 2.1 eV17, which explains the color change during reaction, the shift of absorption onset in the diffuse reflection spectra and the observation under optical microscopy. To confirm


8

Page 9 of 17 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


this composition of the solid-state reaction end-product, a Pawley profile fitting involving three phases, MAI, MA3Sb2I9 and Sb2S3, was again performed on the XRD pattern from 5° to 60° two theta range (Figure 2c). All peaks in the observed pattern can be accounted for and the Pawley fit yields a very small difference curve between the observed and calculated patterns, with an overall goodness-of-fit value of 1.18, Rp value of 0.067 and Rwp value of 0.092, suggesting that the reaction product mixture is composed of these three phases with good confidence. This result indicates that the thermodynamically stable product of the reaction between MAI and SbSI should be MA3Sb2I9 and Sb2S3 instead of the mixed sulfide and iodide perovskite phase MASbSI2, and such reaction will follow the path in the following Equation 2. Because the stoichiometry of the reactants (SbSI and MAI) is 1:1, there will be excess MAI in the product mixture (hence there are MAI peaks in the XRD pattern, unless the reaction is conducted in an open vessel). Additionally, a solid-state reaction of MAI with SbI3 and Sb2S3, instead of SbSI (with the same overall stoichiometry), was performed at 150 °C for four days. Similar profile fitting of the XRD pattern indicates the product is a mixture of MA3Sb2I9, unreacted Sb2S3 and excess MAI (with only trace amount SbSI detected), as shown in Figure S6. This result further confirms that MA3Sb2I9 and Sb2S3 are the thermodynamically more stable phases. 6 SbSI 3 MAI ⟶ MA Sb I 2 Sb S Equation 2

The stability of the proposed phase MASbSI2 was also studied using DFT calculation. The decomposition energy of MASbSI2 along several pathways were considered. First, we investigate the stability of MASbSI2. We assume that the MASbSI2 is configured in a cubic phase, similar to that in the previous report19, with MA molecules aligned in an antiferroelectric configuration, which is found energetically more stable than other configurations, and sulfur


9


Page 10 of 17

atoms occupying the apical sites of the octahedra, as shown in Figure 1a. The relaxed MASbSI2 structure with four formula units (f.u.) has a pseudo-orthorhombic unit cell with a = 12.11 Å, b =12.14 Å, c = 11.87 Å and α = 89.45°, β = 91.01°, γ = 89.80°. It is obvious that the Sb octahedra are highly distorted along the apical direction, where the Sn-S bond lengths are ~2.3 Å and ~3.7 Å, respectively (as for the previous report19). To evaluate the thermodynamic stability of MASbSI2, we considered the following two decomposition paths: 3 MASbSI ⟶ SbI 3 MAI Sb S Equation 3 MASbSI ⟶ SbSI MAI Equation 4 The decomposition energy is defined as ∆ = !"#$% − '(#$()$%. Therefore, a negative ∆ indicates the instability of the reactant(s) with respect to the products. For reactions shown in Eqs. 3 and 4, the calculated ∆ is -1.00 eV/f.u. and -0.38 eV/f.u., respectively, indicating MASbSI2 is unstable. It is believed that MA molecules are dynamically disordered; however, for the DFT calculations, the dipole of the MA molecule must be situated in a specific orientation. Neighboring MA molecules with definite dipole moments have dipole-dipole interactions that would increase the total energy, thus reducing the calculated stability. To examine the possible dipole interaction effects on the thermodynamic stability of MASbSI2, we replace the MA by the largest alkali metal, Fr. For FrSbSI2, the calculated decomposition energy is -0.96 eV/f.u. and -0.36 eV/f.u., respectively, for the reactions in Eqs. 3 and 4 (with MA replaced by Fr). While reducing the magnitude of the negative decomposition energy slightly, the results again suggest that the mixed sulfide and iodide perovskite is unstable (Figure 3a).


10

Page 11 of 17 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. Decomposition energies of different reaction pathways of (a) Equation 3 and 4 and (b) Equation 2 with Fr as the A cation. Next, we investigate the energetics of the reaction of Equation 2 to examine the likelihood of forming MA3Sb2I9. Our experimental data (determined from Pawley fitting of XRD pattern) shows that MA3Sb2I9 has a space group of P63/mmc with lattice parameters of a = b = 8.544 Å and c = 21.488 Å, very close to literature values.24 For DFT calculations, similar to the case of MASbSI2, to eliminate the influence of the dipole interactions of the MA molecules and better simulate the real crystal structure (in which the MA cation is rotationally disordered), we replace the MA by Fr and evaluate the energetics of the reaction in Eq. 2. The relaxed structure of Fr3Sb2I9 has a space group of P63/mmc with lattice parameters of a = b = 8.621 Å and c = 21.783 Å, a reasonable match compared to the experimental value. Total energy calculations show that, with Fr replacement, the products in Eq. 2 are 0.44 eV/f.u. lower in energy than the reactants, which agrees with our experimental observation of the formation of MA3Sb2I9 and Sb2S3 (Figure 3b).


11


Page 12 of 17

While the MASbSI2 phase does not appear to be thermodynamically stable under conditions examined experimentally or theoretically, this does not preclude the possibility of forming the phase under non-equilibrium conditions–e.g., for a film strained at an interface. To further understand the electronic properties of this proposed MASbSI2 phase, its band structure and the density of states (DOS) were calculated based on the relaxed structure with HSE06 functional25, as shown in Figure 4 (the computational approach is discussed in more detail in the Supplemental Information). The band structure diagram shows a direct band gap of 0.83 eV, which is substantially smaller than the reported 2.0 eV value.19 The conduction band minimum (CBM) derives mainly from Sb p orbitals while the valence band maximum (VBM) is composed of I and S p orbitals. Additionally, the band edges are relatively dispersive in the vicinity of the Γ point, pointing to good carrier mobilities. Overall, these characteristics indicate that such mixed sulfide and iodide phases could potentially be promising for PV applications, if it were possible to stabilize them in thin film form.

Figure 4. HSE06 band structure and DOS of the proposed MASbSI2.

In conclusion, we have demonstrated that, in contradiction to a recent report,19 synthesis of the lead-free mixed sulfide and iodide perovskite phase MASbSI2 using solid state reaction methods


12

Page 13 of 17 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


yields the ternary/binary products MA3Sb2I9 and Sb2S3. The formation of these phases has been unambiguously confirmed using X-ray diffraction pattern fitting and diffuse reflectance spectroscopic analysis. DFT calculations also corroborate the experimental findings that MASbSI2 should be thermodynamically less stable compared to the corresponding binary and ternary phases. Although these results indicate that it is less likely to create the mixed sulfide and iodide perovskite phase under thermal equilibrium conditions, we cannot exclude the possibility that similar lead-free mixed chalcogenide and halide phases may still form as metastable phases under nonequilibrium conditions. It is also possible that these phases could be stabilized in a two-dimensional perovskite lattice and/or by choosing chalcogen/halogen anions with more similar sizes (for example, S and Br, or Se and I). These mixed anion lead-free perovskite phases can potentially be interesting for PV applications if synthesized, due to suitable band gap energy and electronic characteristics.

ASSOCIATED CONTENT ACKNOWLEDGMENT The information, data, or work presented herein was funded in part by the Office of Energy Efficiency and Renewable Energy (EERE), U.S. Department of Energy, under Award Number DE-EE0006712. This work was performed in part at the Duke University Shared Materials Instrumentation Facility (SMIF), a member of the North Carolina Research Triangle Nanotechnology Network (RTNN), which is supported by the National Science Foundation (Grant ECCS-1542015) as part of the National Nanotechnology Coordinated Infrastructure (NNCI). All opinions expressed in this paper are the authors’ and do not necessarily reflect the


13


Page 14 of 17

policies and views of DOE or NSF. See the Supporting Information section of this article for more information. Supporting Information. Synthesis procedures, characterization and computational details, optical microscope images, Tauc plots of reactant and product mixture, XRD patterns of products during reaction progression. AUTHOR INFORMATION Corresponding Author *[email protected] *[email protected] Notes #

These authors contributed equally.

The authors declare no competing financial interests.

REFERENCES (1) National Renewable Energy Laboratory. Research Cell Record Efficiency Chart. https://www.nrel.gov/pv/assets/images/efficiency-chart.png (accessed April 25,2018). (2) Burschka, J.; Pellet, N.; Moon, S.-J.; Humphry-Baker, R.; Gao, P.; Nazeeruddin, M. K.; Gratzel, M. Sequential Deposition As A Route to High-Performance Perovskite-Sensitized Solar Cells. Nature 2013, 499, 316-319. (3) Jeon, N. J.; Noh, J. H.; Yang, W. S.; Kim, Y. C.; Ryu, S.; Seo, J.; Seok, S. I. Compositional Engineering of Perovskite Materials for High-Performance Solar Cells. Nature 2015, 517, 476.


14

Page 15 of 17 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) Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T. Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. J. Am. Chem. Soc. 2009, 131, 6050-6051. (5) 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, 643647. (6) Yang, W. S.; Park, B.-W.; Jung, E. H.; Jeon, N. J.; Kim, Y. C.; Lee, D. U.; Shin, S. S.; Seo, J.; Kim, E. K.; Noh, J. H. et al. Iodide Management in Formamidinium-Lead-Halide–Based Perovskite Layers for Efficient Solar Cells. Science 2017, 356, 1376-1379. (7) Hao, F.; Stoumpos, C. C.; Chang, R. P. H.; Kanatzidis, M. G. Anomalous Band Gap Behavior in Mixed Sn and Pb Perovskites Enables Broadening of Absorption Spectrum in Solar Cells. J. Am. Chem. Soc. 2014, 136, 8094-8099. (8) Noel, N. K.; Stranks, S. D.; Abate, A.; Wehrenfennig, C.; Guarnera, S.; Haghighirad, A.-A.; Sadhanala, A.; Eperon, G. E.; Pathak, S. K.; Johnston, M. B. et al. Lead-free Organic-Inorganic Tin Halide Perovskites for Photovoltaic Applications. Energy Environ. Sci. 2014, 7, 3061-3068. (9) Hao, F.; Stoumpos, C. C.; Cao, D. H.; Chang, R. P. H.; Kanatzidis, M. G. Lead-Free SolidState Organic–Inorganic Halide Perovskite Solar Cells. Nat. Photonics 2014, 8, 489. (10) Lee, S. J.; Shin, S. S.; Kim, Y. C.; Kim, D.; Ahn, T. K.; Noh, J. H.; Seo, J.; Seok, S. I. Fabrication of Efficient Formamidinium Tin Iodide Perovskite Solar Cells through SnF2– Pyrazine Complex. J. Am. Chem. Soc. 2016, 138, 3974-3977. (11) Liao, W.; Zhao, D.; Yu, Y.; Grice, C. R.; Wang, C.; Cimaroli, A. J.; Schulz, P.; Meng, W.; Zhu, K.; Xiong, R. G. et al. Lead‐Free Inverted Planar Formamidinium Tin Triiodide Perovskite Solar Cells Achieving Power Conversion Efficiencies up to 6.22%. Adv. Mater. 2016, 28, 9333-9340.


15


Page 16 of 17

(12) Saparov, B.; Hong, F.; Sun, J.-P.; Duan, H.-S.; Meng, W.; Cameron, S.; Hill, I. G.; Yan, Y.; Mitzi, D. B. Thin-Film Preparation and Characterization of Cs3Sb2I9: A Lead-Free Layered Perovskite Semiconductor. Chem. Mater. 2015, 27, 5622-5632. (13) Lehner, A. J.; Fabini, D. H.; Evans, H. A.; Hébert, C.-A.; Smock, S. R.; Hu, J.; Wang, H.; Zwanziger, J. W.; Chabinyc, M. L.; Seshadri, R. Crystal and Electronic Structures of Complex Bismuth Iodides A3Bi2I9 (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics. Chem. Mater. 2015, 27, 7137-7148. (14) Hebig, J.-C.; Kühn, I.; Flohre, J.; Kirchartz, T. Optoelectronic Properties of (CH3NH3)3Sb2I9 Thin Films for Photovoltaic Applications. ACS Energy Lett. 2016, 1, 309-314. (15) Park, B. W.; Philippe, B.; Zhang, X.; Rensmo, H.; Boschloo, G.; Johansson, E. M. J. Bismuth Based Hybrid Perovskites A3Bi2I9 (A: Methylammonium or Cesium) for Solar Cell Application. Adv. Mater. 2015, 27, 6806-6813. (16) Boopathi, K. M.; Karuppuswamy, P.; Singh, A.; Hanmandlu, C.; Lin, L.; Abbas, S. A.; Chang, C. C.; Wang, P. C.; Li, G.; Chu, C. W. Solution-processable Antimony-based Lightabsorbing Materials Beyond Lead Halide Perovskites. J. Mater. Chem. A 2017, 5, 20843-20850. (17) Jiang, F.; Yang, D.; Jiang, Y.; Liu, T.; Zhao, X.; Ming, Y.; Luo, B.; Qin, F.; Fan, J.; Han, H. et al. Chlorine-Incorporation-Induced Formation of the Layered Phase for Antimony-Based Lead-Free Perovskite Solar Cells. J. Am. Chem. Soc. 2018, 140, 1019-1027. (18) Khazaee, M.; Sardashti, K.; Sun, J.-P.; Zhou, H.; Clegg, C.; Hill, I. G.; Jones, J. L.; Lupascu, D. C.; Mitzi, D. B. A Versatile Thin-Film Deposition Method for Multidimensional Semiconducting Bismuth Halides. Chem. Mater. 2018, 3538-3544. (19) Nie, R.; Mehta, A.; Park, B.-w.; Kwon, H.-W.; Im, J.; Seok, S. I. Mixed Sulfur and IodideBased Lead-Free Perovskite Solar Cells. J. Am. Chem. Soc. 2018, 140, 872-875.


16

Page 17 of 17 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) Hong, F.; Saparov, B.; Meng, W.; Xiao, Z.; Mitzi, D. B.; Yan, Y. Viability of Lead-Free Perovskites with Mixed Chalcogen and Halogen Anions for Photovoltaic Applications. J. Phys. Chem. C. 2016, 120, 6435-6441. (21) Nowak, M.; Szperlich, P. Temperature Dependence of Energy Band Gap and Spontaneous Polarization of SbSI Nanowires. Opt. Mater. 2013, 35, 1200-1206. (22) Tamilselvan, M.; Bhattacharyya, A. J. Antimony Sulphoiodide (SbSI), A Narrow Band-Gap Non-oxide Ternary Semiconductor With Efficient Photocatalytic Activity. RSC Adv. 2016, 6, 105980-105987. (23) Itzhaik, Y.; Niitsoo, O.; Page, M.; Hodes, G. Sb2S3-Sensitized Nanoporous TiO2 Solar Cells. J. Phys. Chem. C. 2009, 113, 4254-4256. (24) Zaleski, J.; Jakubas, R.; Sobczyk, L.; Mróz, J. Properties and Structural Phase Transitions of (CH3NH3)3Sb2I9. Ferroelectrics 1990, 103, 83-90. (25) Krukau, A. V.; Vydrov, O. A.; Izmaylov, A. F.; Scuseria, G. E. Influence of the Exchange Screening Parameter on the Performance of Screened Hybrid Functionals. J. Chem. Phys. 2006, 125, 224106.


17

Phase Stability and Electronic Structure of Prospective Sb-Based

Recommend Documents