ZnO core-shell pn homojunction photodetector and its fast UV sensing properties

In this article, we report the fabrication and characterization of ZnO core-shell p-n homojunction photodetector (PD) based on p-ZnO (ZnO:Na) nanorods and n-ZnO (ZnO:Al) film. Hexagonal wurtzite ZnO:Na nanorods in single crystalline has been demonstrated by XRD and TEM analysis. Hall measurement shows that ZnO:Na nanorods exhibit p-type conduction with a hole concentration in the order of 10(17) cm(-3). Low temperature PL analysis confirms the shallow acceptor level of 128 +/- 3 meV of p-ZnO:Na nanorods. And the ZnO homojunction exhibits good rectifying behavior. Under the irradiation of UV light, the ZnO homojunction PD exhibits fast on/off response with a rising and recovery time of smaller than similar to 82 ms. This work not only demonstrates the realization of p-ZnO:Na by a simple CVD method, but also sheds the light on constructing ZnO p-n homojunction based UV PDs and LEDs.