Photosensitivity of semiconductor-protein systems

Abstract

Photovoltaic effects have been revealed in a new class of semiconductor/B heterojunctions. Considering various semiconductor materials (Si, GaAs, InSe, CdSiAs₂, ZnGeP₂, and CuGaS₂) and native proteins, we found that it is possible to create photosensitive structures on their basis and managed to prepare them. The photoelectric parameters of the semiconductor/B systems are measured for the first time. It is shows that these structures have a photosensitivity whose level is characteristic of solid-state photoconverters. The spectral dependences of the quantum efficiency of photoconvertion are studied. The window effect for such structures has been established: the long-wavelength boundary of photosensitivity is determined by the energy gap of a semiconductor, whereas the short-wavelength boundary in the vicinity of 3.55 is explained by the quasi-interband transitions in the wide-gap component common for all the heterojunctions—the protein. The conclusion is drawn that the structures of this new class based on crystals of anisotropic semiconductors can be used as broad-band photoconverters of the natural radiation and photoanalyzers of a linearly polarized radiation.