Investigation of the Few‐Layer Black Phosphorus Degradation by the Photonic Measurements

Abstract

Few‐layer black phosphorus (FLBP) is a 2D material that gains worldwide interest for its possible applications, mainly in electronics and optoelectronics. However, as FLBP is prone to a degradation process under environmental conditions, there is a need for a monitoring method allowing investigation of its surface quality. Among many techniques, optoelectronic ones have unique advantages of fast response, non‐contact, and non‐invasive operation. In this paper, a photonic method is presented for this purpose with a focus on the earliest stages of the degradation process. Measurements are performed using a fiber‐optic interferometer working at the wavelength of 1310 nm. Series of material characterization measurements, including scanning electron microscopy, X‐ray photoelectron spectroscopy, and Raman spectroscopy investigations are performed to examine the FLBP using a well‐established methodology. Two samples—with liquid exfoliated FLBP and with layers of supernatant—prepared in two different production processes are investigated over 3 h. A detailed presentation of the degradation process is provided. The results prove that the surface monitoring of FLBP is possible by registering optical signal changes correlated with the changes in optical parameters caused by the proceeding degradation process.