Vapor‐Deposited Cs2AgBiCl6 Double Perovskite Films toward Highly Selective and Stable Ultraviolet Photodetector. Issue 11 (22nd April 2020)

• Record Type: Journal Article
• Authors: Wang, Ming; Zeng, Peng; Wang, Zenghui; Liu, Mingzhen
• Is Part Of: Advanced science. Volume 7:Issue 11(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-04-22
• Subjects: double perovskite films -- selective detection -- sequential vapor deposition -- ultraviolet photodetectors; Science -- Periodicals; 505
• DOI: 10.1002/advs.201903662
• Languages: English
• ISSNs: 2198-3844

Abstract

Abstract: Double perovskites have shown great potentials in addressing the toxicity and instability issues of lead halide perovskites toward practical applications. However, fabrication of high‐quality double perovskite thin films has remained challenging. Here, sequential vapor deposition is used to fabricate high‐quality Cs2 AgBiCl6 perovskite films with balanced stoichiometry, superior morphology, and highly oriented crystallinity, with an indirect bandgap of 2.41 eV. Using a diode structure, self‐powered Cs2 AgBiCl6 ultraviolet (UV) photodetectors are demonstrated with high selectivity centered at 370 nm, with low dark current density (≈10 −7 mA cm −2 ), high photoresponsivity (≈10 mA W −1 ), and detectivity (≈10 12 Jones). Its detectivity is among the highest in all double‐perovskite‐based photodetectors reported to date and surpassing the performance of other perovskite photodetectors as well as metal oxide in the UV range. The devices also show excellent environmental and irradiation stability comparable to state‐of‐the‐art UV detectors. The findings help pave the way toward application of double perovskites in optoelectronic devices. Abstract : Lead‐free Cs2 AgBiCl6 double perovskite films with balanced stoichiometry, compact morphology, and high crystallinity are fabricated by a sequential vapor deposition method. Their application is explored as an ultraviolet photodetector which realizes low dark current density (≈10 −7 mA cm −2 ), high detectivity (≈10 12 Jones), and stability (4 months). This work reveals the potential of Cs2 AgBiCl6 double perovskites in ultraviolet detection.