Effects of low-energy hydrogen ion implantation on optical properties of ZnO nanowires

The low-energy hydrogen ions (2 keV; 1 × 1015 to 1 × 1018 cm−2 per dose) implantation was used to study the passivation effect of defects and photoluminescence properties of ZnO nanowires. The implanted H+ effectively passivated deep level native defects, making the visible emission at 500 nm disappear completely and the UV emission (380 nm) of nanowires enhance for seven times. H+ implantation at higher dose induced a strongly new violet emission broad peak (around 410 nm) which may originate from the hydrogen related complex of defects. However, this violet emission disappeared after annealing in argon atmosphere at 300 °C, confirming that the new violet emission is related to hydrogen. All emission peaks vanished due to the formation of a large quantity of nonradiative recombination centers at high dose implantation. This controllable method of hydrogen doping may find potential application in UV/violet optoelectronic and especially in nano-optoelectronic devices.