The Bright Side and the Dark Side of Hybrid Organic Inorganic Perovskites

Wladek Walukiewicz; Shu Wang; Xinchun Wu; Rundong Li; Matthew P. Sherburne; Bo Wu; Tze Chien Sun; Joel W. Ager; Mark D. Asta

doi:10.1021/acs.jpcc.0c08263

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arXiv · 2010.12119

The Bright Side and the Dark Side of Hybrid Organic Inorganic Perovskites

Wladek Walukiewicz·Shu Wang·Xinchun Wu·Rundong Li·Matthew P. Sherburne·Bo Wu·Tze Chien Sun·Joel W. Ager·Mark D. Asta

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Abstract

The previously developed bistable amphoteric native defect (BAND) model is used for a comprehensive explanation of the unique photophysical properties and for understanding the remarkable performance of perovskites as photovoltaic materials. It is shown that the amphoteric defects in donor (acceptor) configuration capture a fraction of photoexcited electrons (holes) dividing them into two groups: higher energy bright and lower energy dark electrons (holes). The spatial separation of the dark electrons and the dark holes and the k-space separation of the bright and the dark charge carriers reduce electron hole recombination rates, emulating the properties of an ideal photovoltaic material with a balanced, spatially separated transport of electrons and holes. The BAND model also offers a straightforward explanation for the exceptional insensitivity of the photovoltaic performance of polycrystalline perovskite films to structural and optical inhomogeneities. The blue-shifted radiative recombination of bright electrons and holes results in a large anti-Stokes effect that provides a quantitative explanation for the spectral dependence of the laser cooling effect measured in perovskite platelets.

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Wladek Walukiewicz, Shu Wang, Xinchun Wu, Rundong Li, Matthew P. Sherburne, Bo Wu, Tze Chien Sun, Joel W. Ager, Mark D. Asta. 2020-10-23. The Bright Side and the Dark Side of Hybrid Organic Inorganic Perovskites. https://doi.org/10.1021/acs.jpcc.0c08263

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