Influence of Synthesis Conditions on the Lifetime of Excess Charge Carriers in Monograin Powders with Kesterite Structure

Resumo

By solid-phase synthesis, macrocrystalline Cu_2 − δZn_2 − xSn_xS_4 − ySe_y monograin powders have been prepared, the chemical composition of which was shown by XRD and Raman spectroscopy to be different in powder fractions of different sizes formed during the synthesis. The influence of synthesis conditions on the decay kinetics of photogenerated charge carriers in different fractions has been studied using the frequency–time-resolved microwave photoconductivity method. The characteristic photoresponse half-life, τ_1/2, increased with increasing grain size. The smallest values of the lifetime were observed for the fraction with sizes of 50–70 μm (τ_1/2 <5 ns), and the largest values were for the fraction with a grain size of 70–90 μm (τ_1/2 ~ 12 ns).