Highly Sensitive Broadband Phototransistors Based on Gradient Tin/Lead Mixed Perovskites. Issue 3 (21st November 2022)

• Record Type: Journal Article
• Authors: Loi, Hok‐Leung; Cao, Jiupeng; Liu, Chun‐Ki; Xu, Yang; Li, Mitch Guijun; Yan, Feng
• Is Part Of: Small. Volume 19:Issue 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-21
• Subjects: broadband -- detectivity -- perovskites -- phototransistors -- responsivity; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202205976
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Highly sensitive broadband photodetectors are critical to numerous cutting‐edge technologies such as biomedical imaging, environment monitoring, and night vision. Here, phototransistors based on mixed Sn/Pb perovskites are reported, which demonstrate ultrahigh responsivity, gain and specific detectivity in a broadband from ultraviolet to near‐infrared region. The interface properties of the perovskite phototransistors are optimized by a special three‐step cleaning‐healing‐cleaning treatment, leading to a high hole mobility in the channel. The highly sensitive performance of the mixed Sn/Pb perovskite phototransistors can be attributed to the vertical compositional heterojunction automatically formed during the film deposition, which is helpful for the separation of photocarriers thereby enhancing a photogating effect in the perovskite channel. This work demonstrates a convenient approach to achieving high‐performance phototransistors through tuning compositional gradient in mixed‐metal perovskite channels. Abstract : Highly sensitive broadband phototransistors based on single‐layer mixed Sn/Pb‐based perovskites are prepared by proper antisolvent treatment and three‐step solution‐processed passivation. Benefitting from the compositional gradient that is favorable for charge separation in the perovskite layer, the optimized device exhibits a high responsivity up to 10 5 A W −1 in a broad wavelength region from ultraviolet to near infrared.