Temperature controlled synthesis of boron carbon nitride nanosheets and study of their bandgap modulation and nonlinear optical properties

Abstract

This work reports a novel mechanism to synthesize boron carbon nitride (BCN) nanosheets with varying carbon concentration where the whole process is controlled by temperature variation. The morphology, layer numbers, crystallinity, chemical composition and bonding of synthesized BCN nanosheets were confirmed by Field emission scanning electron microscopy (FESEM), Atomic force microscopy (AFM), Transmission electron microscopy (TEM), X-Ray photoelectron spectroscopy (XPS) and Energy Dispersive X-Ray Analysis (EDX). Molecular configuration and bonding vibration of the nanosheets and their linear optical and 3rd-order nonlinear optical properties were analyzed by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, UV–Vis spectroscopy and Z-scan technique respectively. The bandgap estimated from UV–Vis absorption data matches well with the theoretical values calculated by ab initio density functional theory (DFT) thus confirming the formation of BCN nanosheets. The thermal treatment of hBN in the graphitic environment is demonstrated to control the tuning of the morphological, structural, linear, and nonlinear optical characteristics of synthesized BCN nanosheets which currently pave the way of new opportunities for the development of tunable bandgap-based electronics and photonic devices.