Abstract
Recently, halide perovskites have emerged as a promising material for device applications. Lead-based perovskites have been widely explored, while investigation of the optical properties of lead-free perovskites remains limited. Lead-halide perovskite single crystals have shown light-induced positive photoconductivity, and as lead-free perovskites are optically active, they are expected to demonstrate similar properties. However, we report here light-induced negative photoconductivity with slow recovery in lead-free Cs3Bi2Cl9 perovskite. Femtosecond transient reflectance (fs-TR) spectroscopy studies further reveal that these electronic transport properties are due to the formation of light-activated metastable trap states within the perovskite crystal. The figure of merits were calculated for Cs3Bi2Cl9 single-crystal detectors, including responsivity (17 mA/W), detectivity (6.23 × 1011 Jones), and the ratio of current in dark to light (∼7160). These observations for Cs3Bi2Cl9 single crystals, which were optically active but showed retroactive photocurrent on irradiation, remain unique for such materials.
Original language | English (US) |
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Pages (from-to) | 2286-2292 |
Number of pages | 7 |
Journal | The Journal of Physical Chemistry Letters |
DOIs | |
State | Published - Mar 1 2021 |
Bibliographical note
KAUST Repository Item: Exported on 2021-03-05Acknowledgements: N.K.T. acknowledges a UGC Fellowship. S.S. acknowledges the Ministry of Electronics and Information Technology research grant DIC-1377-PHY.
ASJC Scopus subject areas
- General Materials Science