Growth of Centimeter-Scale Monolayer and Few-Layer WSe2 Thin Films on SiO2/Si Substrate via Pulsed Laser Deposition

To date, the fabrication of highly uniform large-scale monolayer and few-layer p-type WSe2 throughout the entire substrate, especially on SiO2/Si substrates is significantly challenging and one of the most important issues. Here, the fabrication of highly uniform monolayer and few-layer WSe2 thin films on a centimeter-scale SiO2/Si substrate via pulsed laser deposition is reported. The number of WSe2 layers and the thickness, controlled by varying the number of laser pulses, is determined by transmission electron microscopy analysis. The high uniformity of the as-grown WSe2 thin film on the entire SiO2/Si substrate is verified by the uniform Raman peak position and intensity, estimated by Raman mapping. Using a conventional photolithography process, field effect transistors based on the as-grown WSe2 thin films are fabricated and their electrical characteristic is analyzed.