The The Photoelectric Properties of n-Si–p-(Ge2)1-x-y(ZnSe)x(GaAs1-δBiδ)y Heterostructures

In this paper, the photovoltaic properties of (Ge2)1-x-y(ZnSe)x(GaAs1-δBiδ)y solid solutions grown on silicon substrates are investigated. It is found that the solid solutions (Ge2)1-x-y(ZnSe)x(GaAs1-δBiδ)y possess selective photosensitivity due to the presence of ZnSe, Ge2 and GaAs1-δBiδ components, as well as the difference in the ionisation energy of their covalent bonds. The photoconductivity mechanicms in n-Si-p-(Ge2)1-x-y(ZnSe)x(GaAs1-δBiδ)y heterostructures were analysed based on the Ei values that provided the best fit to the experimental spectrum and Gaussian approximation curves. Photopeaks corresponding to Gaussian curves at the energy levels 1.23 eV, 1.45 eV, 1.64 eV, 1.91 eV, 2.21 eV, and 2.45 eV were observed in the photon energy range: Eph,1 - 0.98÷1.75 eV, Eph,2 - 1.01÷2.03 eV, Eph,3 - 1.15÷2.28 eV, Eph,4 - 1.34÷2.52 eV, Eph,5 - 1.75÷2.71 eV and Eph,6 - 2.1÷2.77 eV. The observation of intermediate states in the photosensitivity spectrum of this solid solution confirmed the presence of nano-objects formed on the basis of ZnSe and Ge2 molecules, as well as GaAs1-δBiδ compounds in these films. It was found that solid solutions (Ge2)1-x-y(ZnSe)x(GaAs1-δBiδ)y have the potential to be used as selective photoactive materials operating in the ranges of infrared and visible radiation.