Substrates and interlayer coupling effects on Mo_1-xW_xSe₂alloys

Two-dimensional (2D) transition metal dichalcogenides alloys are potential materials in the application of photodetectors over a wide spectral range due to their composition-dependent bandgaps. The study of bandgap engineering is important for the application of 2D materials in devices. Here, we grow the Mo_1-xW _x Se₂ alloys on mica, sapphire and SiO₂/Si substrates by chemical vapor deposition (CVD) method. Mo_1-xW _x Se₂ alloys are grown on the mica substrates by CVD method for the first time. Photoluminescence (PL) spectroscopy is used to investigate the effects of substrates and interlayer coupling force on the optical bandgaps of as-grown Mo_1-xW _x Se₂ alloys. We find that the substrates used in this work have an ignorable effect on the optical bandgaps of as-grown Mo_1-xW _x Se₂. The interlayer coupling effect on the optical bandgaps of as-grown Mo_1-xW _x Se₂ is larger than the substrates effect. These findings provide a new way for the future study of the growth and physical properties of 2D alloy materials.