skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Thermally evaporated methylammonium tin triiodide thin films for lead-free perovskite solar cell fabrication

Abstract

Here, we report on the synthesis of methylammonium tin triiodide (MASnI 3) thin films at room temperature by a hybrid thermal evaporation method and their application in fabricating lead (Pb)-free perovskite solar cells. The as-deposited MASnI 3 thin films exhibit smooth surfaces, uniform coverage across the entire substrate, and strong crystallographic preferred orientation along the < 100 > direction. By incorporating this film with an inverted planar device architecture, our Pb-free perovskite solar cells are able to achieve an open-circuit voltage ( V oc) up to 494 mV. The relatively high V oc is mainly ascribed to the excellent surface coverage, the compact morphology, the good stoichiometry control of the MASnI 3 thin films, and the effective passivation of the electron-blocking and hole-blocking layers. Finally, our results demonstrate the potential capability of the hybrid evaporation method to prepare high-quality Pb-free MASnI 3 perovskite thin films which can be used to fabricate efficient Pb-free perovskite solar cells.

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2];  [3];  [1]
  1. The Univ. of Toledo, Toledo, OH (United States)
  2. Nanjing Univ. of Posts & Telecommunications, Nanjing (People's Republic of China)
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S); USDOE SunShot Initiative, Next Generation Photovoltaics 3 Program
OSTI Identifier:
1329460
Report Number(s):
NREL/JA-5900-67300
Journal ID: ISSN 2046-2069; RSCACL
Grant/Contract Number:
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
RSC Advances
Additional Journal Information:
Journal Volume: 6; Journal Issue: 93; Journal ID: ISSN 2046-2069
Publisher:
Royal Society of Chemistry
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; methylammonium tin triiodide; thin films; fabrication; synthesis

Citation Formats

Yu, Yue, Zhao, Dewei, Grice, Corey R., Meng, Weiwei, Wang, Changlei, Liao, Weiqiang, Cimaroli, Alexander J., Zhang, Hongmei, Zhu, Kai, and Yan, Yanfa. Thermally evaporated methylammonium tin triiodide thin films for lead-free perovskite solar cell fabrication. United States: N. p., 2016. Web. doi:10.1039/C6RA19476A.
Yu, Yue, Zhao, Dewei, Grice, Corey R., Meng, Weiwei, Wang, Changlei, Liao, Weiqiang, Cimaroli, Alexander J., Zhang, Hongmei, Zhu, Kai, & Yan, Yanfa. Thermally evaporated methylammonium tin triiodide thin films for lead-free perovskite solar cell fabrication. United States. doi:10.1039/C6RA19476A.
Yu, Yue, Zhao, Dewei, Grice, Corey R., Meng, Weiwei, Wang, Changlei, Liao, Weiqiang, Cimaroli, Alexander J., Zhang, Hongmei, Zhu, Kai, and Yan, Yanfa. 2016. "Thermally evaporated methylammonium tin triiodide thin films for lead-free perovskite solar cell fabrication". United States. doi:10.1039/C6RA19476A. https://www.osti.gov/servlets/purl/1329460.
@article{osti_1329460,
title = {Thermally evaporated methylammonium tin triiodide thin films for lead-free perovskite solar cell fabrication},
author = {Yu, Yue and Zhao, Dewei and Grice, Corey R. and Meng, Weiwei and Wang, Changlei and Liao, Weiqiang and Cimaroli, Alexander J. and Zhang, Hongmei and Zhu, Kai and Yan, Yanfa},
abstractNote = {Here, we report on the synthesis of methylammonium tin triiodide (MASnI3) thin films at room temperature by a hybrid thermal evaporation method and their application in fabricating lead (Pb)-free perovskite solar cells. The as-deposited MASnI3 thin films exhibit smooth surfaces, uniform coverage across the entire substrate, and strong crystallographic preferred orientation along the < 100 > direction. By incorporating this film with an inverted planar device architecture, our Pb-free perovskite solar cells are able to achieve an open-circuit voltage (Voc) up to 494 mV. The relatively high Voc is mainly ascribed to the excellent surface coverage, the compact morphology, the good stoichiometry control of the MASnI3 thin films, and the effective passivation of the electron-blocking and hole-blocking layers. Finally, our results demonstrate the potential capability of the hybrid evaporation method to prepare high-quality Pb-free MASnI3 perovskite thin films which can be used to fabricate efficient Pb-free perovskite solar cells.},
doi = {10.1039/C6RA19476A},
journal = {RSC Advances},
number = 93,
volume = 6,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 3works
Citation information provided by
Web of Science

Save / Share:
  • Photovoltaic applications of perovskite semiconductor material systems have generated considerable interest in part because of predictions that primary defect energy levels reside outside the bandgap. We present experimental evidence that this enabling material property is present in the halide-lead perovskite, CH3NH3PbI3 (MAPbI3), consistent with theoretical predictions. By performing X-ray photoemission spectroscopy, we induce and track dynamic chemical and electronic transformations in the perovskite. These data show compositional changes that begin immediately with exposure to X-ray irradiation, whereas the predominant electronic structure of the thin film on compact TiO2 appears tolerant to the formation of compensating defect pairs of VI andmore » VMA and for a large range of I/Pb ratios. Changing film composition is correlated with a shift of the valence-band maximum only as the halide-lead ratio drops below 2.5. This delay is attributed to the invariance of MAPbI3 electronic structure to distributed defects that can significantly transform the electronic density of states only when in high concentrations.« less
  • The formation mechanism of perovskite methylammonium lead triiodide (CH{sub 3}NH{sub 3}PbI{sub 3}) was studied with in situ X-ray photoelectron spectroscopy (XPS) on successive depositions of thermally evaporated methylammonium iodide (CH{sub 3}NH{sub 3}I) on a lead iodide (PbI{sub 2}) film. This deposition method mimics the “two-step” synthesis method commonly used in device fabrication. We find that several competing processes occur during the formation of perovskite CH{sub 3}NH{sub 3}PbI{sub 3}. Our most important finding is that during vapour deposition of CH{sub 3}NH{sub 3}I onto PbI{sub 2}, at least two carbon species are present in the resulting material, while only one nitrogen speciesmore » is present. This suggests that CH{sub 3}NH{sub 3}I can dissociate during the transition to a perovskite phase, and some of the resulting molecules can be incorporated into the perovskite. The effect of partial CH{sub 3}NH{sub 3} substitution with CH{sub 3} was evaluated, and electronic structure calculations show that CH{sub 3} defects would impact the photovoltaic performance in perovskite solar cells. The possibility that not all A sites in the APbI{sub 3} perovskite are occupied by CH{sub 3}NH{sub 3} is therefore an important consideration when evaluating the performance of organometallic trihalide solar cells synthesized using typical approaches.« less
  • Here we demonstrate a radically different chemical route for the creation of HC(NH2)2PbI3 (FAPbI3) perovskite thin films. This approach entails a simple exposure of as-synthesized CH3NH3PbI3 (MAPbI3) perovskite thin films to HC(=NH)NH2 (formamidine or FA) gas at 150 degrees C, which leads to rapid displacement of the MA+ cations by FA+ cations in the perovskite structure. The resultant FAPbI3 perovskite thin films preserve the microstructural morphology of the original MAPbI3 thin films exceptionally well. Importantly, the myriad processing innovations that have led to the creation of high-quality MAPbI3 perovskite thin films are directly adaptable to FAPbI3 through this simple, rapidmore » chemical-conversion route. Accordingly, we show that efficiencies of perovskite solar cells fabricated with FAPbI3 thin films created using this route can reach -18%.« less
  • Mixed tin (Sn)-lead (Pb) perovskites with high Sn content exhibit low bandgaps suitable for fabricating the bottom cell of perovskite-based tandem solar cells. In this work, we report on the fabrication of efficient mixed Sn-Pb perovskite solar cells using precursors combining formamidinium tin iodide (FASnI 3) and methylammonium lead iodide (MAPbI 3). The best-performing cell fabricated using a (FASnI 3) 0.6(MAPbI 3) 0.4 absorber with an absorption edge of ~1.2 eV achieved a power conversion efficiency (PCE) of 15.08 (15.00)% with an open-circuit voltage of 0.795 (0.799) V, a short-circuit current density of 26.86(26.82) mA/cm 2, and a fill factormore » of 70.6(70.0)% when measured under forward (reverse) voltage scan. In conclusion, the average PCE of 50 cells we have fabricated is 14.39 ± 0.33%, indicating good reproducibility.« less