Photoluminescence and conductivity of As2S3 and As2S5 glasses with small gold additions

The photo luminescence (PL) spectra and the excitations of glassy semiconductors of stoichiometric and nonstoichiometric compounds (AS(2)S(3))(100-x)Au-x, (AS(2)S(5))(100-x)Au-x, (0less than or equal toxless than or equal to0.04) at T=77 K are studied for the first time. The PL spectrum in the glasses of nonstoichiometric compound with small gold additions splits in two bands one of which being responsible for gold. The experimental results for temperature dependence of the glass conductivity of (As2S3)(1-x)Au-x and (AS(2)S(5))(1-x)Au-x (0.04greater than or equal toxgreater than or equal to0) are presented for the first time. There are found: two fractures on the temperature dependence of the conductivity in compounds with small gold concentration, and an abnormal behaviour of the conductivity in the temperature range 300 K<T<360 K. The major part of the impurity atoms enters into the volume of the glass semiconductor. saturates all its valence bonds by forming a series of solid solutions and this leads to a change of band gap E, A small part of impurity atoms, having an unusual closest neighbourhood, do not saturate the valence bonds, and, as a result, forms an electrical active impurity level that defines the conductivity.