Epitaxial growth of ZnO films on si(111)

In this paper, we report the growth of ZnO films on silicon substrates using a pulsed laser deposition technique. These films were deposited on SO (111) directly as well as by using thin buffer layers of AIN and GaN. All the films were found to have c-axis-preferred orientation aligned with normal to the substrate. Films with AIN and GaN buffer layers were epitaxial with preferred in-plane orientation, while those directly grown on Si(111) were found to have random in-plane orientation. A decrease in the frequency of the E-2((2)) Raman mode and a red shift of the band-edge photoluminescence peak due to the presence of tensile strain in the film, was observed. Various possible sources for the observed biaxial strain are discussed.