Исследование свойств двумерных пленок МоS-=SUB=-2-=/SUB=- и WS-=SUB=-2-=/SUB=-, синтезированных химическим газофазным методом

Abstract

Abstract Molybdenum- and tungsten-disulfide films are synthesized by chemical-vapor deposition. The set of optimal synthesis parameters (temperature, time, and amount and ratio of precursors) is established at which MoS_2 domains with maximum lateral sizes of up to 250 μm on sapphire and MoS_2 and WS_2 domains up to 80 μm in size on SiO_2 can be grown. Domain intergrowth leads to the formation of homogeneous single-layer MoS_2 films. The Raman spectra of the synthesized films contain two characteristic peaks corresponding to the atomic vibrations in MoS_2 and WS_2. Photoluminescence of the single-layer and bilayer MoS_2 films with a maximum intensity of 670 ± 2 nm and of the single-layer WS_2 films with a maximum intensity of 630 ± 2 nm is detected. The photoluminescence spectral maps (the dependences of the photoluminescence intensity on the luminescence and excitation-light wavelengths) are measured. According to the measured data, the photoluminescence excitation spectrum of MoS_2 has a maximum at 350 ± 5 nm and the photoluminescence excitation spectrum of WS_2 has a maximum at 330 ± 5 nm. The I – V characteristics of the synthesized films are photosensitive in the visible spectral range.