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.