2D Ruddlesden-Popper Perovskite with Ordered Phase Distribution for High-Performance Self-Powered Photodetectors

2D Ruddlesden-Popper perovskites exhibit great potential in optoelectronic devices for superior stability compared with their 3D counterparts. However, to achieve a high level of device performance, it is crucial but challenging to regulate the phase distribution of 2D perovskites to facilitate charge carrier transfer. Herein, using a solvent additive method (adding a small amount of dimethyl sulfoxide (DMSO) in N,N-dimethylformamide (DMF)) combined with a hot-casting process, the phase distribution of (PEA)(2)MA(3)Pb(4)I(13) (PEA(+) = C6H5CH2CH2NH3+, MA(+) = CH3NH3+) perovskite can be well controlled and the Fermi level of perovskites along the film thickness direction can achieve gradient distribution. The increased built-in potential, oriented crystal, and improved crystal quality jointly contribute to the high photoresponse of devices in the entire response spectrum range. The optimum device exhibits a characteristic detection peak at 570 nm with large responsivity/detectivity (0.44 A W-1/3.38 x 10(12) Jones), ultrafast response speed with a rise/fall time of 20.8/20.6 mu s, and improved stability. This work suggests the possibility of manipulating the ordered phase distribution of 2D perovskites toward high-performance and stable optoelectronic conversion devices.

Automated summary

This research successfully controlled the phase distribution of 2D perovskites using a solvent additive method and hot-casting process, which improved photoresponse of devices. The optimized device showed high performance, stability, and fast response speed in optical-electronic conversion.