Epitaxial Growth Of UV Optoelectric Material ZnO And The Study Of Its Character

ZnO is a novel wide-gap semiconductor, which has a bandgap of 3.37eV, Combining with high excitonic gain and large exciton binging energy (60meV), It is a suitable candidate for the UV optoelectronic device applications. The binding energy of ZnO can be further improved in the low Dimension material such as superlattice and multi-quantum well, which can be achieved by laser molecular beam epitaxy L-MBE.In this paper, ZnO films have been prepared by DC reactive sputtering on different substrates (K4 glass, Si (1 1 1 ), Si (001)), the effect of O/Ar ratio, substrate temperature and annealing process on the quality of ZnO films were investigated, It is found that the crystallinity and orientation degree are improved after annealing process. After investigation and analysis of the samples by XRD, the growing and annealing parameters are optimized , High-oriented ZnO films with XRD FWHM of 0.1?was obtained at a substrate temperature of 350癈 and the ratio of O/Ar is 1:2.Optical transmittance of around 85% was observed in the visible region of the spectrum for the ZnO films , the highest optical transmittance is 95% for our samples. KrF excimer laser with a wavelength of 248nm is used to pump the ZnO samples at room temperature. Photoluminescence spectra at room temperature shows near band-edge (NBE) emission of 400nm which is originated from the combination of excitons.P doping of ZnO is a key step to obtain pn junctions and to realize the electric current injected emission of UV-emitting diode . The factor of effective p doping and the self-compensation of IPD in ZnO films has been discussed in detail in this paper, which will give some advice on p doping of ZnO.