First-Principles Analysis of Radiative Recombination in Lead-Halide Perovskites

Journal Article · 05 September 2018 · ACS Energy Letters

DOI: https://doi.org/10.1021/acsenergylett.8b01297 · OSTI ID:1468978

Zhang, Xie ^[1]; Shen, Jimmy-Xuan ^[2]; Wang, Wennie ^[1]; Van de Walle, Chris G. ^[1]

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1. Univ. of California, Santa Barbara, CA (United States). Materials Dept.
2. Univ. of California, Santa Barbara, CA (United States). Dept. of Physics

Slow radiative recombination due to a slightly indirect band gap has been proposed to explain the high efficiency of lead-halide perovskite solar cells. In this work, we calculate the radiative recombination rate from first principles for the prototypical lead-halide perovskite, MAPbI₃ (MA=CH₃NH₃). Since the structure is dynamic, with the MA molecule rotating even at room temperature, we determine the momentum mismatch between the band edges as a function of the orientation of the MA molecule. Our results demonstrate that the indirect nature of the band gap suppresses the radiative recombination rate by less than a factor of two, and that the radiative recombination coefficient is as high as in traditional direct-gap semiconductors. Our study provides a rigorous assessment of the radiative recombination mechanisms and their relation to the high efficiency of lead-halide perovskite solar cells, and will provide a sound basis for accurate modeling.

• Research Organization: Univ. of California, Santa Barbara, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Contributing Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
• Grant/Contract Number: SC0010689; AC02-05CH11231
• OSTI ID: 1468978
• Journal Information: ACS Energy Letters, Vol. 3; ISSN 2380-8195
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English