Reconfiguring the band-edge states of photovoltaic perovskites by conjugated organic cations

Journal Article · Fri Feb 05 00:00:00 UTC 2021 · Science

DOI: https://doi.org/10.1126/science.abd4860 · OSTI ID:1765472

Xue, Jingjing  ^[1]; Wang, Rui  ^[2]; Chen, Xihan  ^[3]; Yao, Canglang ^[4]; Jin, Xiaoyun  ^[5]; Wang, Kai-Li  ^[6]; Huang, Wenchao  ^[7]; Huang, Tianyi  ^[2]; Zhao, Yepin  ^[2]; Zhai, Yaxin  ^[3]; Meng, Dong  ^[2]; Tan, Shaun  ^[2]; Liu, Ruzhang  ^[5]; Wang, Zhao-Kui  ^[6]; Zhu, Chenhui  ^[8]; Zhu, Kai  ^[3]; Beard, Matthew C.  ^[3]; Yan, Yanfa  ^[4]; Yang, Yang  ^[2]

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1. Univ. of California, Los Angeles, CA (United States); University of California, Los Angeles
2. Univ. of California, Los Angeles, CA (United States)
3. National Renewable Energy Lab. (NREL), Golden, CO (United States)
4. Univ. of Toledo, OH (United States)
5. Yangzhou Univ. (China)
6. Soochow Univ., Suzhou (China)
7. Monash Univ., Clayton, VIC (Australia)
8. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

The band edges of metal-halide perovskites with a general chemical structure of ABX₃ (A, usually a monovalent organic cation; B, a divalent cation; and X, a halide anion) are constructed mainly of the orbitals from B and X sites. Hence, the structural and compositional varieties of the inorganic B–X framework are primarily responsible for regulating their electronic properties, whereas A-site cations are thought to only help stabilize the lattice and not to directly contribute to near-edge states. We report a π-conjugation–induced extension of electronic states of A-site cations that affects perovskite frontier orbitals. The π-conjugated pyrene-containing A-site cations electronically contribute to the surface band edges and influence the carrier dynamics, with a properly tailored intercalation distance between layers of the inorganic framework. Lastly, the ethylammonium pyrene increased hole mobilities, improved power conversion efficiencies relative to that of a reference perovskite, and enhanced device stability.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States); Univ of California, Los Angeles, CA (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office; USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC36-08GO28308; EE0008751
• OSTI ID: 1765472
• Report Number(s): NREL/JA--5900-77174
• Journal Information: Science, Journal Name: Science Journal Issue: 6529 Vol. 371; ISSN 0036-8075
• Publisher: AAASCopyright Statement
• Country of Publication: United States
• Language: English