Properties and applications of ZnO
K. J. Chang
Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
Zinc oxide (ZnO) has attracted much attention because of possible applications for wide-gap optoelectronic devices. Alloying this material with Mg extends applications to the uv range. Despite advantages such as the availability of large area substrates, high radiation resistance, and low material costs, one major problem remains to be solved; it is difficult to obtain low resistivity p-type ZnO. In this work I talk about the compensation mechanism for acceptors in ZnO, based on first-principles pseudopotential calculations within the local-density-functional approximation. Based on the formation energies for various defects, I discuss the defect stability, formation, and concentration as a function of the Fermi level. I show how to enhance doping solubility and doping efficiency to achieve low-resistivity p-type samples. Finally, I discuss the optical charcateristics of ZnO doped with acceptors, recent progress in fabricating light emitting diodes based on zinc oxide, and growth and applications of ZnO nanostructures.