Additive Modulated Perovskite Microstructures for High Performance Photodetectors

Organic-inorganic hybrid perovskites have been widely used as light sensitive components for high-efficient photodetectors due to their superior optoelectronic properties. However, the unwanted crystallographic defects of perovskites typically result in high dark current, and thus limit the performance of the device. Herein, we introduce a simple route of microstructures control in MAPbI₃ perovskites that associates with introducing an additive of 3,3,4,4-benzophenonetetracarboxylic dianhydridean (BPTCD) for crystallization adjustment of the perovskite film. The BPTCD additive can facilitate the formation of high-quality perovskite film with a compact and nearly pinhole-free morphology. Through characterizing the molecular interactions, it was found that the carbonyl groups in BPTCD is the key reason that promoted the nucleation and crystallization of MAPbI₃ . As a result, we obtained high-efficient and stable perovskite photodetectors with low dark current of 9.98 × 10⁻⁸ A at −0.5 V, an on/off ratio value of 10³, and a high detectivity exceeding 10¹² Jones over the visible region.