Annealing time dependent structural, morphological, optical and electrical properties of RF sputtered p-type transparent conducting SnO2/Al/SnO2 thin films

Transparent p-type conducting SnO2/Al/SnO2 multilayer films were fabricated on quartz substrates by radio frequency (RF) sputtering using SnO2 and Al targets. The deposited films were annealed at a fix temperature of 500 °C for different time durations (1–8 h). The effect of annealing time on the structural, morphological, optical and electrical performances of SnO2/Al/SnO2 multilayer films was studied. X-ray diffraction (XRD) results show that all the p-type conducting films possess polycrystalline SnO2 with tetragonal rutile structure. Hall-effect results indicate that 500 °C for 1 h is the optimum annealing condition for p-type SnO2/Al/SnO2 multilayer films, resulting in a hole concentration of 1.14×1018 cm–3 and a low resistivity of 1.38 Ω·cm, respectively. The optical transmittance of the p-type SnO2/Al/SnO2 multilayer films is above 80% within annealing time range of 1–8 h, showing maximum for the films annealed for 1 h.