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Ma JJ, Zheng JJ, Chen Y, Ren Q, Zhang J, Wang BT. Intrinsic ultralow lattice thermal conductivity in lead-free halide perovskites Cs 3Bi 2X 9 (X = Br, I). Phys Chem Chem Phys 2024; 26:21801-21809. [PMID: 39101765 DOI: 10.1039/d4cp02005g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/06/2024]
Abstract
Lead-free halide perovskites have recently garnered significant attention due to their rich structural diversity and exceptionally ultralow lattice thermal conductivity (κL). Here, we employ first-principles calculations in conjunction with self-consistent phonon theory and Boltzmann transport equations to investigate the crystal structure, electronic structure, mechanical properties, and κLs of two typical vacancy-ordered halide perovskites, denoted with the general formula Cs3Bi2X9 (X = Br, I). Ultralow κLs of 0.401 and 0.262 W mK-1 at 300 K are predicted for Cs3Bi2Br9 and Cs3Bi2I9, respectively. Our findings reveal that the ultralow κLs are mainly associated with the Cs rattling-like motion, vibrations of halide polyhedral frameworks, and strong scattering in the acoustic and low-frequency optical phonon branches. The structural analysis indicates that these phonon dynamic properties are closely relevant to the bonding hierarchy. The presence of the extended Bi-X antibonding states at the valence band maximum contributes to the soft elastic lattice and low phonon group velocities. Compared to Cs3Bi2Br9, the face-sharing feature and weaker bond strength in Cs3Bi2I9 lead to a softer elasticity modulus and stronger anharmonicity. Additionally, we demonstrate the presence of wave-like κC in Cs3Bi2X9 by evaluating the coherent contribution. Our work provides the physical microscopic mechanisms of the wave-like κC in two typical lead-free halide perovskites, which are beneficial to designing intrinsic materials with the feature of ultralow κL.
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Affiliation(s)
- Jiang-Jiang Ma
- School of Physics and Information Engineering, Shanxi Normal University, Taiyuan 030031, China.
| | - Jing-Jing Zheng
- Department of Physics, Taiyuan Normal University, Jinzhong, 030619, China
| | - Yuxi Chen
- School of Physics and Information Engineering, Shanxi Normal University, Taiyuan 030031, China.
| | - Qingyong Ren
- Institute of High Energy Physics, Chinese Academy of Sciences (CAS), Beijing 100049, China.
- Spallation Neutron Source Science Center, Dongguan 523803, China
- Guangdong Provincial Key Laboratory of Extreme Conditions, Dongguan, 523803, China
| | - Junfeng Zhang
- School of Physics and Information Engineering, Shanxi Normal University, Taiyuan 030031, China.
- College of Physics and Electronic Engineering, Hainan Normal University, Haikou 571158, China
| | - Bao-Tian Wang
- Institute of High Energy Physics, Chinese Academy of Sciences (CAS), Beijing 100049, China.
- Spallation Neutron Source Science Center, Dongguan 523803, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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Porwal S, Paul M, Dixit H, Mishra S, Singh T. Investigation of Defects in Cs
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SnI
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‐Based Double Perovskite Solar Cells Via SCAPS‐1D. ADVANCED THEORY AND SIMULATIONS 2022. [DOI: 10.1002/adts.202200207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Shivam Porwal
- Functional Materials and Device Laboratory School of Energy Science and Engineering Indian Institute of Technology Kharagpur Kharagpur 721302 India
| | - Mrittika Paul
- Functional Materials and Device Laboratory School of Energy Science and Engineering Indian Institute of Technology Kharagpur Kharagpur 721302 India
| | - Himanshu Dixit
- Functional Materials and Device Laboratory School of Energy Science and Engineering Indian Institute of Technology Kharagpur Kharagpur 721302 India
| | - Snehangshu Mishra
- Functional Materials and Device Laboratory School of Energy Science and Engineering Indian Institute of Technology Kharagpur Kharagpur 721302 India
| | - Trilok Singh
- Functional Materials and Device Laboratory School of Energy Science and Engineering Indian Institute of Technology Kharagpur Kharagpur 721302 India
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