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Title: CsSnI[subscript 3]: Semiconductor or Metal? High Electrical Conductivity and Strong Near-Infrared Photoluminescence from a Single Material. High Hole Mobility and Phase-Transitions

Abstract

CsSnI{sub 3} is an unusual perovskite that undergoes complex displacive and reconstructive phase transitions and exhibits near-infrared emission at room temperature. Experimental and theoretical studies of CsSnI{sub 3} have been limited by the lack of detailed crystal structure characterization and chemical instability. Here we describe the synthesis of pure polymorphic crystals, the preparation of large crack-/bubble-free ingots, the refined single-crystal structures, and temperature-dependent charge transport and optical properties of CsSnI{sub 3}, coupled with ab initio first-principles density functional theory (DFT) calculations. In situ temperature-dependent single-crystal and synchrotron powder X-ray diffraction studies reveal the origin of polymorphous phase transitions of CsSnI{sub 3}. The black orthorhombic form of CsSnI{sub 3} demonstrates one of the largest volumetric thermal expansion coefficients for inorganic solids. Electrical conductivity, Hall effect, and thermopower measurements on it show p-type metallic behavior with low carrier density, despite the optical band gap of 1.3 eV. Hall effect measurements of the black orthorhombic perovskite phase of CsSnI{sub 3} indicate that it is a p-type direct band gap semiconductor with carrier concentration at room temperature of {approx} 10{sup 17} cm{sup -3} and a hole mobility of {approx} 585 cm{sup 2} V{sup -1} s{sup -1}. The hole mobility is one of the highestmore » observed among p-type semiconductors with comparable band gaps. Its powders exhibit a strong room-temperature near-IR emission spectrum at 950 nm. Remarkably, the values of the electrical conductivity and photoluminescence intensity increase with heat treatment. The DFT calculations show that the screened-exchange local density approximation-derived band gap agrees well with the experimentally measured band gap. Calculations of the formation energy of defects strongly suggest that the electrical and light emission properties possibly result from Sn defects in the crystal structure, which arise intrinsically. Thus, although stoichiometric CsSnI{sub 3} is a semiconductor, the material is prone to intrinsic defects associated with Sn vacancies. This creates highly mobile holes which cause the materials to appear metallic.« less

Authors:
; ; ; ; ; ; ; ;  [1];  [2]
  1. (NWU)
  2. (
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
National Science Foundation (NSF)
OSTI Identifier:
1047915
Resource Type:
Journal Article
Journal Name:
J. Am. Chem. Soc.
Additional Journal Information:
Journal Volume: 134; Journal Issue: (20) ; 05, 2012; Journal ID: ISSN 0002-7863
Country of Publication:
United States
Language:
ENGLISH
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CARRIER DENSITY; CHARGE TRANSPORT; CRYSTAL STRUCTURE; DEFECTS; ELECTRIC CONDUCTIVITY; FUNCTIONALS; HALL EFFECT; HEAT TREATMENTS; HOLE MOBILITY; INSTABILITY; OPTICAL PROPERTIES; ORIGIN; PEROVSKITE; PHOTOLUMINESCENCE; SYNCHROTRONS; SYNTHESIS; THERMAL EXPANSION; VACANCIES; X-RAY DIFFRACTION

Citation Formats

Chung, In, Song, Jung-Hwan, Im, Jino, Androulakis, John, Malliakas, Christos D., Li, Hao, Freeman, Arthur J., Kenney, John T., Kanatzidis, Mercouri G., and OmniPV). CsSnI[subscript 3]: Semiconductor or Metal? High Electrical Conductivity and Strong Near-Infrared Photoluminescence from a Single Material. High Hole Mobility and Phase-Transitions. United States: N. p., 2012. Web. doi:10.1021/ja301539s.
Chung, In, Song, Jung-Hwan, Im, Jino, Androulakis, John, Malliakas, Christos D., Li, Hao, Freeman, Arthur J., Kenney, John T., Kanatzidis, Mercouri G., & OmniPV). CsSnI[subscript 3]: Semiconductor or Metal? High Electrical Conductivity and Strong Near-Infrared Photoluminescence from a Single Material. High Hole Mobility and Phase-Transitions. United States. doi:10.1021/ja301539s.
Chung, In, Song, Jung-Hwan, Im, Jino, Androulakis, John, Malliakas, Christos D., Li, Hao, Freeman, Arthur J., Kenney, John T., Kanatzidis, Mercouri G., and OmniPV). Mon . "CsSnI[subscript 3]: Semiconductor or Metal? High Electrical Conductivity and Strong Near-Infrared Photoluminescence from a Single Material. High Hole Mobility and Phase-Transitions". United States. doi:10.1021/ja301539s.
@article{osti_1047915,
title = {CsSnI[subscript 3]: Semiconductor or Metal? High Electrical Conductivity and Strong Near-Infrared Photoluminescence from a Single Material. High Hole Mobility and Phase-Transitions},
author = {Chung, In and Song, Jung-Hwan and Im, Jino and Androulakis, John and Malliakas, Christos D. and Li, Hao and Freeman, Arthur J. and Kenney, John T. and Kanatzidis, Mercouri G. and OmniPV)},
abstractNote = {CsSnI{sub 3} is an unusual perovskite that undergoes complex displacive and reconstructive phase transitions and exhibits near-infrared emission at room temperature. Experimental and theoretical studies of CsSnI{sub 3} have been limited by the lack of detailed crystal structure characterization and chemical instability. Here we describe the synthesis of pure polymorphic crystals, the preparation of large crack-/bubble-free ingots, the refined single-crystal structures, and temperature-dependent charge transport and optical properties of CsSnI{sub 3}, coupled with ab initio first-principles density functional theory (DFT) calculations. In situ temperature-dependent single-crystal and synchrotron powder X-ray diffraction studies reveal the origin of polymorphous phase transitions of CsSnI{sub 3}. The black orthorhombic form of CsSnI{sub 3} demonstrates one of the largest volumetric thermal expansion coefficients for inorganic solids. Electrical conductivity, Hall effect, and thermopower measurements on it show p-type metallic behavior with low carrier density, despite the optical band gap of 1.3 eV. Hall effect measurements of the black orthorhombic perovskite phase of CsSnI{sub 3} indicate that it is a p-type direct band gap semiconductor with carrier concentration at room temperature of {approx} 10{sup 17} cm{sup -3} and a hole mobility of {approx} 585 cm{sup 2} V{sup -1} s{sup -1}. The hole mobility is one of the highest observed among p-type semiconductors with comparable band gaps. Its powders exhibit a strong room-temperature near-IR emission spectrum at 950 nm. Remarkably, the values of the electrical conductivity and photoluminescence intensity increase with heat treatment. The DFT calculations show that the screened-exchange local density approximation-derived band gap agrees well with the experimentally measured band gap. Calculations of the formation energy of defects strongly suggest that the electrical and light emission properties possibly result from Sn defects in the crystal structure, which arise intrinsically. Thus, although stoichiometric CsSnI{sub 3} is a semiconductor, the material is prone to intrinsic defects associated with Sn vacancies. This creates highly mobile holes which cause the materials to appear metallic.},
doi = {10.1021/ja301539s},
journal = {J. Am. Chem. Soc.},
issn = {0002-7863},
number = (20) ; 05, 2012,
volume = 134,
place = {United States},
year = {2012},
month = {10}
}