The scanning microscope for semiconductor characterization: Photocurrent, photovoltage and electrolyte electroreflectance imaging at the n-MoSe2/I- interface

Digital images of photocurrent, photovoltage and electrolyte electroreflectance at the n-MoSe2\electrolyte interface, with micrometric lateral resolution, are presented under different experimental conditions. Inhomogeneities in the surface distribution of the parameters controlling both the semiconductor photoresponse and the kinetics of transfer of photogenerated charge carriers to the electrolyte can be inferred from these images. A clear influence of the semiconductor topography on these photoeffects is evidenced. So, the photoresponse is observed to decrease in regions with structural surface defects, due to the existence of associated bulk recombination centers. The state of the van der Waals surface in contact with the electrolyte is shown to be a main factor determining the photoelectrochemical behavior of the n-MoSe2 electrode.