Doped Zinc Oxide Thin Films And Optical Properties

ZnO is a compound semiconductor with a wide direct bandgap. Its exciton binding energy is 60meV and is hexagonal wurtzite structure. Due to their excellent physical and chemical properties, ZnO films have many realized and potential applications. And they can be integrated with some semiconductor materials. Therefore, it widely used in many field. In this dissertation, we report the systematical work on preparation, and optical properties of ZnO and Mn or Co doped ZnO films.The target materials were prepared by the sol - gel method, The films were deposited on silicon(Si) and quartz(SiO₂) substrates distinctly by PLD, and mixed gas of O₂ during deposition. The effects of deposition, such as temperature of substrate have be studied in detail. The microstructure, superficial appearance and atomic ingredient of films were characterized by XRD,AFM and EDX.The XRD measurements show all the films have (002) preferred orientation. Only if the temperature of substrate is too high or Mn,Co doped quantity too more, the structure of films will be changed. The AFM measurements show the films grains are uniformity and dense, if the temperature of substrate and Mn,Co doped quantity are appropriate. And EDX show the films were deposited in same component by PLD basically.The optical quality of ZnO thin film and Mn, Co doped ZnO thin film have been studied, and Discovered the thin film appear emissions in the wave length of 380nm, 427nm,and 510nm, Moreover the blue emission in 427nm is a prominent emission. The Substrate temperature,the doping element and the doping density will effect the thin film's emission. Moreover Mn, Co doped thin film changed the energy gap of ZnO.In addition, the diaphaneity of Mn, Co doped ZnO thin film were also studied, Discovered the highest thin film transmittance is up to 90%. And along with doping quantity increasing, thin films transmittance reduce. Believed that it connect with the thin film's defections.