Highly Sensitive Self-Powered 2D Perovskite Photodiodes with Dual Interface Passivations

2D perovskites have attracted intensive attention by virtue of their excellent optical and electrical properties along with good stabilities. Herein, a highly sensitive self-powered photodiode based on (PEA)(2)(MA)(4)Pb5I16 (PEA=C6H5(CH2)NH3, MA=CH3NH3) 2D perovskite is demonstrated by dual interface passivations. The Al2O3 bottom passivation can reduce the pinhole defects in the 2D perovskite film and suppress the trap-related recombination loss, bringing forward much reduced dark current and increased photocurrent. The poly (methyl methacrylate) (PMMA) top passivation can encapsulate the 2D perovskite film and thus improve the stability of the device. These results show that the 2D perovskite-based photodiode with dual interface passivations exhibits a large photo-to-dark current ratio of 10(7), a fast response speed of 597 ns and a linear dynamic range of 160 dB without bias. Responsivity (R) and detectivity (D*) respectively reach 0.36 A W-1 and 5.4 x 10(12) Jones under 532 nm laser illumination at a power density of 1.5 nW cm(-2). Moreover, the dual interface passivated device exhibits good stabilities. This work paves the road for developing low-cost, low-power, solution processed image sensors.

Automated summary

In this study, a highly sensitive self-powered photodiode based on 2D perovskite material was demonstrated with dual interface passivations. The bottom passivation reduced defects and trap-related recombination loss, while the top passivation improved device stability. The dual interface passivated device showed a large photo-to-dark current ratio, fast response speed, and wide dynamic range.