p-type field effect transistor and UV-photoconductive characteristics of Na doped ZnMgO thin films

摘要

In this study, the authors have presented results for fabricated ZnO based FET and the UV-photoconductive characteristics of Na doped ZnMgO thin films. The electrical measurements confirmed that the conductivity of the Na doped ZnMgO thin film is p-type, and the carrier mobility was estimated to be 2.3 cm~2V~(-1)S~(-1). Moreover, after exposed to the 365 nm ultraviolet light, the Na doped ZnMgO thin films still exhibited p-type behavior under gate voltage ranging from -5 to 2 V, and the Id increased a little while the carrier mobility did not change much. The photocurrent was measured under a bias of 6 V in air at room temperature. The films performed a higher current intensity after the illumination. The instantaneous rise of the photocurrent was completed when exposed to the 365 nm ultraviolet for 20 s, after switching the ultraviolet off the photocurrent decayed in a slower rate. The enhance rate of photocurrent was about 1.33%. Conclusively, Na is a considerable acceptor dopant for making high quality p-type ZnO films, and the tiny change in the photocurrent of p-type Na doped ZnMgO thin film made it relatively stable when fabricating LEDs and other optoelectronic devices.