Characteristics of p-type ZnTe films grown on sputtered ZnO by using pulsed laser deposition

Abstract

p-type ZnTe films were grown on a sputtered ZnO layer by using pulsed laser deposition in a nitrogen atmosphere. As the growth temperature was increased from 220 to 320 A degrees C, hole concentrations in the ZnTe films decreased significantly from 1.3 x 10(18) to 1.4 x 10(16) cm(-3) while the hole mobility increased slightly. The film growth at higher temperatures resulted in the loss of p-type behavior in the ZnTe films and on a deterioration in the film's crystallinity. The degradation of crystal quality and p-type characteristics of ZnTe are most likely due to instable nitrogen bonding in ZnTe at high temperatures and to the large lattice mismatch of similar to 25% between the ZnTe (111) and the ZnO (0001) crystal planes.