Influence of electron injection on the photoresponse of ZnO homojunction diodes

Forward bias electron injection into the p side of a p-n homojunction was shown to result in an improved response of the ZnO photodiodes. Injection of about 25 C of charge yielded a nearly 2.5-fold increase of photocurrent at 350 nm. This improvement was correlated with the increase of the diffusion length of minority electrons in p-type ZnO:Sb as determined by electron beam induced current measurements. It is suggested that the increase of the diffusion length is related to the carrier trapping on nonionized acceptor levels. (c) 2006 American Institute of Physics.