Crystallization ability and optical and electrical properties of Ge$_{10}$(Se–Te)$_{90}$ and Ge$_{30}$(Se–Te)$_{70}$ chalcogenide glassy semiconductors

Chalcogenide glassy semiconductors of the ternary system Ge–Se–Te along the Ge$_{10}$(Se–Te)$_{90}$ and Ge$_{30}$(Se–Te)$_{70}$ joins have been synthesized. The crystallization ability, near-IR transmission spectra, and temperature dependence of the electrical conductivity of the alloys obtained have been studied. It is shown that chalcogenide glassy semiconductors along the Ge$_{10}$(Se–Te)$_{90}$ join have a lower softening and crystallization points compared with semiconductors belonging to the Ge$_{30}$(Se–Te)$_{70}$ join. A change in the electrical conductivity of samples by several orders of magnitude occurs upon a phase transition from the glassy to the crystalline state. Compositions of chalcogenide glassy semiconductors in the Ge–Se–Te system are found, which have $\alpha<$ 1 cm$^{-1}$ absorption coefficient at wavelengths of $\lambda\approx$ 1.5 $\mu$m and exhibit a thermally induced phase transition from the glassy to the crystalline state.