Arsenic-doped ZnO films fabricated on silicon substrates by pulsed laser ablation

We report the preparation of arsenic-doped ZnO films on silicon(I 0 0) using ZnO/AS(2)O(3) targets by pulsed laser ablation. AS(2)O(3) was used as a p-type dopant source material for arsenic doping in ZnO. Hall effect measurements show that the stable p-type films with hole carrier concentration of about 10(16) cm(-3), resistivity of about 3.35 Omega cm, and Hall mobility of 26.41 cm(2)/V s were obtained using 0.5-1 at.% ZnO:As target. XRD results indicate that some defects induced by As doping in ZnO lattice structure promoted the p-type electrical conduction. The results of post-annealing indicate that defects such as vacancies introduced by As did not act as capturing traps of acceptors but as one of elements forming acceptor. XPS spectra confirm that most of the contained As existed as AS(Zn). Based on these results, the possibility of an AS(Zn)-2V(Zn) complex forming a shallow acceptor was discussed. (C) 2007 Elsevier B.V. All rights reserved.