Steady-state and transient photocurrents of As-S-Sb-Te amorphous thin films

Abstract

In the present work some nanostructured quaternary chalcogenides of the As-S-Sb-Te system have been investigated by a photoelectric method. The spectral distribution of steadystate photocurrent Iph=(λ) and the relaxation curves of photocurrent Iph=(t) were registered at positive and negative polarity of the applied voltage to the top Al illuminated electrode. In the spectral distribution of steady-state photocurrent, for the amorphous thin films As1.17S2.7Sb0.83Te0.40, As1.04S2.4Sb0.96Te0.60, As0.63S2.7Sb1.37Te0.30, and As0.56S2.4Sb1.44Te0.60 in the wavelength range λ=0.50÷0.92 mm (2.48÷1.35 eV) some maxima were detected, which are the result of the presence of binary clusters As2S3, Sb2S3 and Sb2S3. The photovoltaic method was used to obtain the value of the band gap width, which was about Eg =1.41 eV.