Structure and photosensitive homojunctions based on Pb1−xSnxSe epitaxial films

The growth of epitaxial films of Pb1 − x Sn x Se solid solutions of different chemical compositions (x = 0.02–0.05) on freshly cleaved BaF2(111) faces and the structure of these films have been investigated. Photosensitive p-n homojunctions have been prepared on their basis. The homojunctions are fabricated in a unified technological cycle without breaking vacuum based on n- and p-type films of high structural quality (W 1/2 = 90–100″) that were grown using an additional selenium vapor source. The photosensitivity peak is found to shift to longer wavelengths with an increase in the Sn content in the films grown; this effect is explained by narrowing the band gap with a change in the composition.