Structural, optical and transport properties of SxZnO

In this paper, S-doped ZnO (SxZnO) was prepared using sol-gel method at different S amounts. The structural, optical and transport properties were investigated. The introduction of S atoms into the ZnO network was found to lower the crystallization level which results in reducing the crystallite size up to x=0.3. The doping process is confirmed by the observed peak at ~610 cm−1 in the ATR spectrum related to the Zn-S linking. EDX mapping shows a homogeneous distribution of S atoms on the particles surface. The best compromise between the band gap (Eg=2.96 eV), the charge carriers (NA=2.139×1022 cm−3), the conductivity (σ=5.56×10−4 Ω−1 m−1) and the mobility (µ=16.26×10−14 m2 V−1 s−1) is obtained for x=0.1. The conduction mechanism is assumed by small hopping polaron. The S-doping has impacted positively the photocatalytic activity of ZnO, with particularly high performance for S0.2ZnO.