Photovoltaic effect and optical absorption in MoS2

An investigation of the Schottky barriers of a number of metals on natural P-type MoS₂ was undertaken. The spectral dependence of the photovoltaic effect of all the metal barriers show two distinct features at 1.38 and 1.68 eV below the direct bandgap at 1.8 eV. A low energy edge at 1.2 eV is invariably observed for metal barriers on MoS₂. Absorption measurements performed over the same energy range indicate that the features observed in the photoresponse spectra are related to indirect transitions in MoS₂, in agreement with recent band calculations. Preliminary data indicate that MoS₂ based Schottky barrier solar cells may be of interest.