Heteroepitaxial Growth and Doping of ZnO for Optoelectronic Applications

摘要

This is the final report of AFOSR grant Number F49620-01-1-0454. No cost extension for one year (31 August/04 to Sept.1/05) was granted by AFOSR. Summary of the research accomplishments duration the total duration 31 August 2001 - Sept. 1/2005 is presented. C- axis oriented ZnO films and nano rods have been grown by rf sputtering and pulse laser deposition (PLD). Thin films of Znl- xMgxO, Znl-xAlxO, and magnetic ion substituted ZnMO (M= Co, Mn, Fe, Gd) have been investigated. ZnO, ZnCoO, ZnMnO nano-particles have been synthesized which clearly showed quantum confinement effect. MgO/ZnO multilayer and ZnAlO films deposited by PLD showed c-axis growth and wide band gap above -6 eV, which is suitable for UV detectors. Mn, Co, and Fe substituted ZnO and ZnS show nearly similar optical behavior, but ZnMnO showed magnetic behavior by SQUID at 5 K. ZnO films could not be doped p-type by rf sputtering, probably due to very high ionization energy required for nitrogen as p-dopant. Several magnetic ion substituted ZnO showed ferromagnetism at lower temperatures, but ZnxCol-xFe2O4.