Photosensitivity of semiconductor-protein systems

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. (C) 2000 MAIK "Nauka/Interperiodica".