This work presents the characterization of As-S-Sb-Te nanostructured polycrystalline semiconductors by X-ray fluorescence (XRF), X-ray diffraction (XRD), electron microscopy (SEM), optical as well as photoelectric methods. The XRD patterns have been shown the presence of amorphous and nanocrystalline phases with the main structural units As2S3, Sb2S3 and Sb2Те3. The IR transmission spectra show a high transparence just with a single weak absorption band about ν=2340 cm-1 caused of the presence of H2S impurity. It was also observed that for the alloys of As11.2S48.0Sb28.8Te12.0 and As20.8S48.0Sb19.2Te12.0, with an increase in the number of As atoms, the transmission in the IR region also increase. The maximum of steady-state photoconductivity for both materials, measured in the linear portion of I-V characteristics, is situated around =0.96 m.