Type Inversion and Certain Physical Properties of Spray Pyrolysed SnO2:Al Films for Novel Transparent Electronics Applications

Aluminium doped tin oxide films have been deposited onto glass substrates by using a simplified and low cost spray pyrolysis technique. The Al doping level varies between 0 and 30 at.% in the step of 5 at.%. The resistivity (ρ) is the minimum (0.38 Ω cm) for 20 at.% of Al doping. The possible mechanism behind the phenomenal zig-zag variation in resistivity with respect to Al doping is discussed in detail. The nature of conductivity changes from n-type to p-type when the Al doping level is 10 at.%. The results show that 20 at.% is the optimum doping level for good quality p-type SnO2:Al films suitable for transparent electronic devices.