Preparation And Properties Of ZnMgO Films And ZnMgO/ZnO Heterojunction

ZnO is a direct wide band-gap semicnoductor with Eg=3.37 eV, and has large exciton binding energy of 60 meV at room temperature. ZnO has a large amount of advantages involving low epitaxial growth temperature and more resistant to radiation damage. In addition, the preparation of ZnO film was easy without strict demands of substrate. Owing to these advantages, ZnO film has attracted wide application prospects as a promising material for optoelectronic devices such as shot wavelength light-emitting diodes, semiconductor lasers diodes and UV detectors. The band gap of Zn1-xMgxO films can be tuned from 3.37 eV to 4.5 eV by changing the volume of Mg through substituting Mg on the position of Zn in the ZnO films, while maintaining the quartzite structure. Moreover, the lattice of Zn1-xMgxO is well matched to ZnO. ZnMgO/ZnO heterosystem allows realizing heterojunction structure in optoelectronic devices, which can improve the emission efficiency of the devices and modulate the working waveband.In this thesis, ZnO, Zn1-xMgxO films and ZnMgO/ZnO heterojunction were deposited by RF magnetron sputtering on Si (100) and glass substrates. The main results are obtained as follows: 1. The high-quality c-axis oriented ZnO films were prepared by RF magnetron sputtering on Si (100) and glass substrate. The influences of experimental parameters such as sputtering power, ratio of O2 to Ar, working pressure and substrate temperature on quality of the films was systematically analyzed and the preferred parameters were obtained. The influence of experimental parameters on transmission of the films was also discussed.2. The high crystalline quality c-axis oriented hexagonal wurtzite Zn1-xMgxO films were prepared on Si (100) and glass substrates by RF magnetron sputtering with using series of Zn1-xMgxO (x=0-0.2) ceramic targets. Firstly, the influence of Mg concentration on crystalline quality and optical properties of Zn1-xMgxO films was discussed. Secondly, the optimal growth conditions of Zn1-xMgxO films were investigated detailed. Finally, the effects of experimental parameters including sputtering power, ratio of O2 to Ar, working pressure and substrate temperature on the optical properties of the films were studies.3. The high crystalline quality c-axis oriented ZnMgO/ZnO heterojunctions were fabricated on Si (100) and ZnO/Si substrate by RF magnetron sputtering for the first time. Through PL measurement, near band edge emissions of ZnO trap layer and ZnMgO barrier layer in ZnMgO/ZnO heterojunction were observed.