Preparation of thin nanostructured n-WSe2 films and their application in semiconductor p-Si photocathodes for hydrogen production by water splitting

The possibilities of modification of the structure and type of conductivity of WSe2 films formed on p-type silicon by thermal treatment of a thin-film precursor, which was preliminarily created by pulsed laser deposition, are studied. Pulsed laser ablation of WSe2 and rhenium targets made it possible to obtain amorphous films WSex (x > 2) containing rhenium atoms and inclusions of β-W nanoparticles. Heat treatment at 450 °C caused the crystallization of the amorphous matrix and the formation of a layered 2H-WSe2 shell surrounded the metal nanoparticles. Doping with rhenium led to the production of n-type WSe2 semiconductor films, which, in terms of their properties (band gap ~ 1.2 eV, high catalytic activity, low resistance to current transport), represent a promising material for creating p-Si photocathodes for efficient light-activated hydrogen evolution in acid solution. Theoretical calculations are carried out, which make it possible to identify local areas on the surface of the formed WSe2 films with enhanced catalytic activity in hydrogen evolution reaction.