Influence of Doping Effect on Zinc Oxide by First-Principles Studies

Zinc oxide, ZnO, can be synthesized into a variety of morphologies including nanowires, nanorods, tetrapods, nanobelts, nanoflowers, nanoparticles, etc., and zinc oxide nanomaterials are promising candidates for nanoelectronics and photonics. Doping in ZnO is one of the most efficient approaches to improve its structure and properties. Here we use the density-functional theory (DFT) to investigate the doping effect of Mn or Co or ZnO. Our calculation results reveal that the transition pressure form the wrutzite (B4) phase to the rocksalt (B1) phase of ZnO decreases with MN or Co doping, which is consistent with the in situ high-pressure X-ray powder diffraction results from synchrotron radiation. For both Mn and Co doping, the doping effect on different structures of ZnO increases in the order: B1 < intermediate tetragonal structure < intermediate hexagonal structure < B4. This causes the decrease of the transition barrier between B4 and B1, which accounts for the decreased transition pressure of Mn- or Co-doped ZnO. Our results provide a theoretical basis for the doping approach to control the structures and properties of ZnO and other similar materials.