Characteristics of plasma hydrogenated ZnO films oriented along the (11-20) plane grown by pulsed laser deposition

Single crystalline phase ZnO layers oriented along the (11-20) plane were successfully grown on (1-102) sapphire substrate by using a modified two-step pulsed laser deposition process. The full width at half maximum of rocking curve for (11-20) ZnO was 430 arc sec. After a hydrogen plasma treatment, the value of surface roughness was decreased from 37.5 to 10.2 nm. And the intensity of ultra-violet emission at 380 nm in cathodoluminescence (CL) spectrum was greatly increased by the hydrogen plasma irradiation. In the time-resolved photoluminescence (TRPL) spectra, the minimum value of decay time was 36 ps after the hydrogen plasma irradiation for 5 min. Especially, CL and TRPL results show the potential of high efficient optoelectronic devices by using the hydrogen plasma treatment.