Optical Filters on the Basis of α -Ag_2Te Thin Films

摘要

The investigation of α-Ag_2Te thin films optical properties by reflection and transmission spectra in IR-range are carried out. In absorption spectra there is an area (0.08 / 0.056 eV) of free carriers absorption with the sharp increasing of the absorption constant. The fine structure of absorption with peak at 0.09 eV and half-width 0.0075 eV connected with absorption of impurity transition by a valence band - small-sized donor is found. For the first time at room temperature in experimental reflection spectrum R (λ) of α-Ag_2Te behind a plasma minimum (1050 cm~(-1)) are detected two further minimum (760cm~(-1) and 500 cm~(-1)), stipulated by interaction of plasmons and long-wave longitudinal optical phonons. In the proper absorption region α (λ) spectrum presents the narrow sharp peak with half-width 0.03eV and steep slope to the short-wave. The indicated features of α-Ag_2Te thin films optical spectrums, allow considering this films as a perspective material for IR optical filters manufacturing.