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

Title: Thin-Film Preparation and Characterization of Cs 3 Sb 2 I 9 : A Lead-Free Layered Perovskite Semiconductor

Abstract

In this study, computational, thin-film deposition and characterization approaches have been used to examine the ternary halide semiconductor Cs3Sb2I9. Cs3Sb2I9 has two known structural modifications, the 0-D dimer form (space group P63/mmc, No. 194) and the 2-D layered form (P$$\bar{3}$$m1, No. 164), which can be prepared via solution and solid state or gas phase reactions, respectively. Our computational investigations suggest that the layered form, which is a one-third Sb-deficient derivative of the ubiquitous perovskite structure, is a potential candidate for high-band-gap photovoltaic (PV) applications. In this work, we describe details of a two-step deposition approach that enables the preparation of large grain (>1 µm) and continuous thin films of the lead-free layered perovskite derivative Cs3Sb2I9. Depending on the deposition conditions, films that are c-axis oriented or randomly oriented can be obtained. The fabricated thin films show enhanced stability under ambient air, compared to methylammonium lead (II) iodide perovskite films stored under similar conditions, and an optical band gap value of 2.05 eV. Photoelectron spectroscopy study yields an ionization energy of 5.6 eV, with the valence band maximum approximately 0.85 eV below the Fermi level, indicating near-intrinsic, weakly p-type character. Density Functional Theory (DFT) analysis points to a nearly direct band gap for this material (less than 0.02 eV difference between the direct and indirect band gaps) and a similar high-level of absorption compared to CH3NH3PbI3. The photoluminescence peak intensity of Cs3Sb2I9 is substantially suppressed compared to that of CH3NH3PbI3, likely reflecting the presence of deep level defects that result in non-radiative recombination in the film, with computational results pointing to Ii, ISb, and VI as being likely candidates. A key further finding from this study is that, despite a distinctly layered structure, the electronic transport anisotropy is less pronounced due to the high ionicity of the I atoms and the strong anti-bonding interactions between the Sb s lone pair states and I p states, which leads to a moderately dispersive valence band.

Authors:
 [1];  [2];  [3];  [4];  [5];  [3];  [3];  [5];  [1]
  1. Department of Mechanical Engineering and Materials Science, Duke University, Box 90300 Hudson Hall, Durham, North Carolina 27708, United States, Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
  2. Department of Physics and Astronomy and Center for Photovoltaics Innovation and Commercialization, The University of Toledo, Toledo, Ohio 43606, United States, Department of Physics, Shanghai University, Shanghai 200444, China
  3. Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 3J5, Canada
  4. Department of Mechanical Engineering and Materials Science, Duke University, Box 90300 Hudson Hall, Durham, North Carolina 27708, United States
  5. Department of Physics and Astronomy and Center for Photovoltaics Innovation and Commercialization, The University of Toledo, Toledo, Ohio 43606, United States
Publication Date:
Research Org.:
Duke Univ., Durham, NC (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1209164
Alternate Identifier(s):
OSTI ID: 1222454
Grant/Contract Number:  
EE0006712
Resource Type:
Published Article
Journal Name:
Chemistry of Materials
Additional Journal Information:
Journal Name: Chemistry of Materials Journal Volume: 27 Journal Issue: 16; Journal ID: ISSN 0897-4756
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE

Citation Formats

Saparov, Bayrammurad, Hong, Feng, Sun, Jon-Paul, Duan, Hsin-Sheng, Meng, Weiwei, Cameron, Samuel, Hill, Ian G., Yan, Yanfa, and Mitzi, David B.. Thin-Film Preparation and Characterization of Cs 3 Sb 2 I 9 : A Lead-Free Layered Perovskite Semiconductor. United States: N. p., 2015. Web. https://doi.org/10.1021/acs.chemmater.5b01989.
Saparov, Bayrammurad, Hong, Feng, Sun, Jon-Paul, Duan, Hsin-Sheng, Meng, Weiwei, Cameron, Samuel, Hill, Ian G., Yan, Yanfa, & Mitzi, David B.. Thin-Film Preparation and Characterization of Cs 3 Sb 2 I 9 : A Lead-Free Layered Perovskite Semiconductor. United States. https://doi.org/10.1021/acs.chemmater.5b01989
Saparov, Bayrammurad, Hong, Feng, Sun, Jon-Paul, Duan, Hsin-Sheng, Meng, Weiwei, Cameron, Samuel, Hill, Ian G., Yan, Yanfa, and Mitzi, David B.. Thu . "Thin-Film Preparation and Characterization of Cs 3 Sb 2 I 9 : A Lead-Free Layered Perovskite Semiconductor". United States. https://doi.org/10.1021/acs.chemmater.5b01989.
@article{osti_1209164,
title = {Thin-Film Preparation and Characterization of Cs 3 Sb 2 I 9 : A Lead-Free Layered Perovskite Semiconductor},
author = {Saparov, Bayrammurad and Hong, Feng and Sun, Jon-Paul and Duan, Hsin-Sheng and Meng, Weiwei and Cameron, Samuel and Hill, Ian G. and Yan, Yanfa and Mitzi, David B.},
abstractNote = {In this study, computational, thin-film deposition and characterization approaches have been used to examine the ternary halide semiconductor Cs3Sb2I9. Cs3Sb2I9 has two known structural modifications, the 0-D dimer form (space group P63/mmc, No. 194) and the 2-D layered form (P$\bar{3}$m1, No. 164), which can be prepared via solution and solid state or gas phase reactions, respectively. Our computational investigations suggest that the layered form, which is a one-third Sb-deficient derivative of the ubiquitous perovskite structure, is a potential candidate for high-band-gap photovoltaic (PV) applications. In this work, we describe details of a two-step deposition approach that enables the preparation of large grain (>1 µm) and continuous thin films of the lead-free layered perovskite derivative Cs3Sb2I9. Depending on the deposition conditions, films that are c-axis oriented or randomly oriented can be obtained. The fabricated thin films show enhanced stability under ambient air, compared to methylammonium lead (II) iodide perovskite films stored under similar conditions, and an optical band gap value of 2.05 eV. Photoelectron spectroscopy study yields an ionization energy of 5.6 eV, with the valence band maximum approximately 0.85 eV below the Fermi level, indicating near-intrinsic, weakly p-type character. Density Functional Theory (DFT) analysis points to a nearly direct band gap for this material (less than 0.02 eV difference between the direct and indirect band gaps) and a similar high-level of absorption compared to CH3NH3PbI3. The photoluminescence peak intensity of Cs3Sb2I9 is substantially suppressed compared to that of CH3NH3PbI3, likely reflecting the presence of deep level defects that result in non-radiative recombination in the film, with computational results pointing to Ii, ISb, and VI as being likely candidates. A key further finding from this study is that, despite a distinctly layered structure, the electronic transport anisotropy is less pronounced due to the high ionicity of the I atoms and the strong anti-bonding interactions between the Sb s lone pair states and I p states, which leads to a moderately dispersive valence band.},
doi = {10.1021/acs.chemmater.5b01989},
journal = {Chemistry of Materials},
number = 16,
volume = 27,
place = {United States},
year = {2015},
month = {8}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1021/acs.chemmater.5b01989

Citation Metrics:
Cited by: 101 works
Citation information provided by
Web of Science

Save / Share: