Post-deposition thermal treatment of sprayed ZnO:Al thin films for enhancing the conductivity

Here, we report the enhanced conductivity of Aluminium doped (2at.%) zinc oxide thin films prepared by simple spray pyrolysis technique. The structural, optical, electrical, morphological and compositional investigations confirm the better quality of films that can be a potential candidate for application in transparent electronics. Most importantly, the film demonstrates an average transmittance of 90 percent with a low resistivity value which was dropped from 1.39×10−2 to 5.10×10−3Ω.cm, after annealing, and a very high carrier concentration in the order of 10×20cm−3. Further, we have used the Swanepoel envelop method to calculate thickness, refractive index and extinction coefficient from the interference patterns observed in the transmission spectra. The calculated figure of merit of the as-deposited sample was 1.4×10−3Ω−1 which was improved to 2.5×10−3Ω−1 after annealing.