Multifunctional zno thin films and nanostructures for optoelectronic applications

Abstract

Zinc Oxide ZnO is a well known semiconductor that has attracted the attention of researchers for a long time because of its wide variety of applications in various fields such as optoelectronic piezoelectric photovoltaic gas sensing cosmetics and vulcanization of rubber ZnO crystallizes in the hexagonal wurtzite structure direct bandgap semiconductor with a band gap of 3 37 eV and free exciton binding energy newlineof 60 meV at room temperature Various forms of ZnO such as nano structures thin films can be grown at a relatively low temperature in the range of 100 C to 250 C and the crystallinity can be improved by annealing at 450 C Another advantage of ZnO is its tunability in the bandgap The tuning of bandgap significantly improves the performance in terms of electronic optoelectronic and photocatalytic properties Therefore ZnO and related materials in the form of thin films and nanostructures have now received increasing attention and recognized as promising candidates for various newlineoptoelectronic applications In this thesis the emphasis is placed on the development of Al and Ga doped ZnO thin films and ZnO nanostructures for a transparent conducting electrode in Silicon thin film solar cells and photo catalytic applications respectively newline newline