Improvement of thermal stability of p‐type ZnO:(Al,N) fabricated by oxidizing Zn₃N₂:Al thin films

Abstract

The authors report the fabrication of p‐type ZnO thin films with improved thermal stability. The p‐type ZnO thin films were obtained by oxidizing Zn3N2:Al thin films in an oxygen ambient. Both Zn3N2:Al and Zn3N2 thin films were deposited on fused silica substrates at 100 °C by megnetron sputtering. X‐ray diffraction (XRD) measurements showed that the ZnO thin films obtained from by oxiding Zn3N2:Al, have preferred (002) orientation. On the other hand, ZnO films obtained by oxidizing Zn3N2 are polycrystalline. The optical band gap of ZnO (3.294 eV) obtained by annealing Zn3N2:Al thin films is narrower than that of the ZnO (3.31 eV) obtained by annealing Zn3N2. P‐type ZnO films were formed by annealing Zn3N2:Al at temperatures above 600 °C. A maximum hole density of 1.4 x 1016 cm‐3 was obtained in a film annealed at 800 °C. In contrast, only n‐type ZnO can be produced from oxidizing Zn3N2. Our results indicate that the Al can stabilize the nitrogen acceptors in ZnO thin films. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Epitaxial Zn3N2 thin films by molecular beam epitaxy: Structural, electrical, and optical properties

“…In the 2000s, the II-nitride material Zn 3 N 2 got into the focus of research, because of the strong interest to fabricate p-type doped ZnO, which would have led to a breakthrough in ZnO-based optoelectronic devices. In this context, several attempts were made to achieve p-ZnO by (partial) oxidation of Zn 3 N 2 [4][5][6][7][8][9][10][11][12] or by fabricating ZnO:N from Zn 3 N 2 targets, as demonstrated by pulsed laser ablation. 13 This also led to increased research activity on Zn 3 N 2 itself, including first demonstrations of Zn 3 N 2 in the field of thin film transistors (TFTs).…”