Properties of the CuInS2surface and the effect of organic layers

This study is devoted to the properties of the CuInS2 (CIS) surface and the effect of thin organic layers on them. The CIS layers under study feature photosensitivity in the range of 1.5–3 eV. A quadratic approximation of the long-wavelength edge of a spectral dependence of the photovoltage yields the band gap E g =1.46±0.02 eV. It is shown that the major contribution to the formation of the barrier near the CIS free surface is made by acceptor levels arranged higher than the CIS valence band top by ∼0.1 and ∼0.2 eV. As a polymeric layer is deposited onto the CIS free surface, the potential barrier height slightly decreases, while the carrier transport efficiency simultaneously increases. As an organic p-type semiconductor is deposited onto the CIS free surface, trapping centers are partially neutralized, and the carrier recombination rate on the CIS film surface decreases.