Preparation And Properties Of Mn-doped ZnO Diluted Magnetic Semiconductors

The research on diluted magnetic semiconductors is one of the frontiers of modern physics.As one of the most promising DMSs candidates, ZnO:Mn has been receiving great attentionrecently. Although remarkable advances have been achieved, there still exist some obstacles inthis area. In this paper, ZnO and ZnO:Mn thin films have been prepared by magnetron sputtering.The structural properties, surface morphology and Mn concentration of samples wereinvestigated, which have been influenced by working pressure, Mn power, Ar flow, substratetemperature, speed, annealing temperature and so on. Here we report our efforts on this topic.1. The XRD results showed the single (002) diffraction peaks for all ZnO:Mn thin filmsexcept deposited at1.0Pa, which indicates the appearance of significant wurtzite structure andwas further evidenced by Raman spectra.2. When changing Mn power, some clear grains appear in the ZnO:Mn film with5.0W Mnpower and the patchy film shows in the sample with10.0W Mn. Combined the measurement ofXRD and Raman, it is found that crystallization of thin films is better when choosing the smallerMn power.3. The half diffraction peak width of (002) direction is narrowest for the sample with Arflow of20sccm, which means the better C axis orientation and more ideal structuralcharacteristics.4. The sample deposited at3.1round/min shows better crystallization and C axis orientation.Raman scattering spectra indicate the speed has little effect on the films’ structure property.5. The influence of substrate temperature on the films is more obvious. The sampledeposited at100℃shows better structural property; surface morphology tends to be smooth andcontinuous at200℃, the smaller grains appear in the film at300℃,where the film shows lessuniform and compact. There are some clusters with little larger size appearing in the film at400℃. For the annealed samples, XRD and Raman results show that the higher annealingtemperature is not good for films’ crystallization. Furthermore, the annealing condition has littleeffect on the defects of samples, but more influence on the samples’ stress.