title: The function of a 60-nm-thick AlN buffer layer in n-ZnO/AlN/p-Si(111).
abstract: ZnO films were prepared on p-Si (111) substrates by using atomic layer deposition. High-resolution x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and I-V measurements were carried out to characterize structural, electrical, and optical properties. After introducing a 60-nm-thick AlN buffer layer, the growth direction of the ZnO films was changed from [10] to [0002]. Meanwhile, the ZnO crystalline quality was significantly improved as verified by both XRD and PL analyses. It has been demonstrated that the reverse leakage current was greatly reduced with the AlN buffer layer. The valence band offsets have been determined to be 3.06, 2.95, and 0.83 eV for ZnO/Si, ZnO/AlN, and AlN/Si heterojunctions, respectively, and the band alignment of ZnO/Si heterojunction was modified to be 0.72 eV after introducing the AlN buffer layer. Our work offered a potential way to fabricate Si-based ultraviolet light-emitting diodes and improve the device performances.
authors: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.
authors: Wei
authors: W
authors: Wang
authors: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.
authors: Chao
authors: C
authors: Chen
authors: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.
authors: Guozhen
authors: G
authors: Zhang
authors: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.
authors: Ti
authors: T
authors: Wang
authors: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.
authors: Hao
authors: H
authors: Wu
authors: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.
authors: Yong
authors: Y
authors: Liu
authors: Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, and School of Physics and Technology, Wuhan University, Wuhan, 430072 People's Republic of China.
authors: Chang
authors: C
authors: Liu
keywords: ALD; AlN buffer layer; Band alignment; Heterojunction