Humidity\nSensing and Photodetection Behavior of Electrochemically\nExfoliated Atomically Thin-Layered\nBlack Phosphorus Nanosheets

Abstract

Recent\ninvestigations on two-dimensional black phosphorus material\nmainly highlight work on few atomic layers and multilayers. It is\nstill unknown if the black phosphorus atomically thin sheet is an\nideal structure for the enhanced gas–solid interactions due\nto its large surface area. To further investigate this concern, we\nhave synthesized few atomic layer thick nanosheets of black phosphorus\nusing an electrochemical exfoliation method. The surface morphology\nand thickness of the nanosheet were identified using AFM, TEM, and\nRaman spectroscopy. The black phosphorus nanosheet thick film device\nwas used for the gas sensing application with exposure to different\nhumidites. Further, the few layer black phosphorus nanosheet based\ntransistor shows good mobility and on/off ratio. The UV light irradiation\non the black phosphorus nanosheet shows good response time. The overall\nresults show that the few layer thick film of black phosphorus nanosheets\nsample exhibits creditable sensitivity and better recovery time to\nbe used in humidity sensor and photodetector applications.