Enhancing UV-C Photoelectron Lifetimes for Avalanche-like Photocurrents in Carbon-Doped Bi₃O₄Cl Nanosheets

Interlayer electric fields in two-dimensional (2D) materialscreatephotoelectron protecting barriers useful to mitigate electron-holerecombination. However, tuning the interlayer electric field remainschallenging. Here, carbon-doped Bi3O4Cl (C:Bi3O4Cl) nanosheets are synthesized using a gas phaseprotocol, and n-type carriers are acquired as confirmed by the transconductancepolarity of nanosheet field effect transistors. Thin C:Bi3O4Cl nanosheets show excellent 266 nm photodetector figuresof merit, and an avalanche-like photocurrent is demonstrated. Decayingbehaviors of photoelectrons pumped by a 266 nm laser pulse (266 nmphotoelectrons) are observed using transient absorption spectroscopy,and a significant 266 nm photoelectron lifetime quality in C:Bi3O4Cl is presented. Built C:Bi3O4Cl models suggest that the interlayer electric field can beboosted by two different carbon substitutions at the inner and outerbismuth sites. This work reports a facile approach to increase theinterlayer electric field in Bi3O4Cl for futureUV-C photodetector applications.