Enhanced the UV response of AlN coated ZnO nanorods photodetector

ZnO nanorods have attracted considerable attention as promising candidate in UV photodetectors (UVPDs) ascribe to their excellent optoelectronic properties. However, the response of UVPDs based on ZnO nanostructures are still low due to a large number of nonradiative centers at interface and electron trapping by the surface states. In this letter, ZnO nanorods with and without AlN coating layer have been grown, the effect of AlN coating layer on the ZnO nanorods and the respective UVPDs performance are carefully studied by various experimental methods. The research on the optical properties indicates that with AlN coating layer, the UV emission intensity of ZnO nanorods significantly enhanced. Furthermore, the photoresponse performance of ZnO nanorods with AlN coating layer has also show an obvious improvement, which is more than one order compare with the bare ZnO nanorods. The enhanced performance is believed to be correlated to the carrier confinement effect together with the surface passivation. This work sheds some lights in searching new structures for next-generation of low cost, large area, and energy efficient optoelectronic devices. •ZnO nanorods with and without AlN coating layer have been grown.•After coating with AlN the photocurrent has been significantly enhanced more than one order.•Emission intensity of ZnO nanorods has been also enhanced after coating with AlN.•Photoresponse enhancement is due to the carrier confinement together with the surface passivation.