Passivation of active recombination centers in ZnO by hydrogen doping

Abstract

The effect of hydrogen doping on luminescence properties of ZnO was investigated. Hydrogen was incorporated in the ZnO crystal by irradiation with an inductively coupled plasma (ICP), in particular, the pulse modulated mode operation of ICP, and the luminescence spectra and hydrogen concentration of the resultant samples were analyzed. A hydrogenated region of 20–100 nm was formed at the sample surface by the irradiation and the concentration of hydrogen was 1017–1018 cm−3. Hydrogen doping improved the ultraviolet emission efficiency of all the samples, and the degree of improvement depended on the initial state (impurity concentration) of the original samples. The most significant improvements were recorded for the sample lightly contaminated with Cu, Al, and Li. The correlation between impurity concentration and hydrogen doping effects is discussed from the viewpoint of charge transfer between hydrogen and the other impurities.

Photoluminescence in MgO-ZnO Nanorods Enhanced by Hydrogen Plasma Treatment

“…30,31 The deep level emission caused by an oxygen vacancy is passivated by trapping hydrogen in the oxygen vacancy resulting in a hydrogen shallow donor bound in an oxygen vacancy as usually admitted. [32][33][34] This finding could benefit the development of many UV light-emitting devices based on ZnO. For instance, hydrogenation has lately been employed to enhance UV emission of the electroluminescence of n-ZnO/p-GaN LEDs.…”

Modulated Induction Thermal Plasmas – Fundamentals and Applications –

“…Ishigaki et al suggested that this difference in the above results between the irradiation of PMITP and the continuous plasma might be attributed to non-equilibrium effects in the PMITP. (19) (20) Here is an example on adoption of PMITP to hydrogen atom doping to ZnO. Many recent investigations on zince oxide (ZnO) have reported about its quantum effect in superlattices, laser emission, and heterojunction light emitting diode.…”

“…On the other hand, our non-equilibrium calculations imply that the above simultaneous control of the increased nitrogen atomic density and the decreased enthalpy flow is due to chemically non-equilibrium effects (23)- (26) . Some other applications of PMITP to surface modification will be introduced briefly (18)- (20) . Finally, a new type of modulated induction thermal plasmas, i.e.…”

“…On the other hand, some studies have been continued for application of the PMITP to materials processings (18)- (23) . For example, Ohashi et al applied the Ar-H 2 PMITP for hydrogen doping to ZnO and found that H atoms can be implanted into ZnO by treatment with an Ar-H 2 PMITP, thereby improving its photoluminescence (19) (20) . We have also investigated to apply the Ar-N 2 PMITP for surface nitridation processing of materials (21)- (23) .…”

Generation of high-power arbitrary-wave-form modulated inductively coupled plasmas for materials processing

“…For example, Ohashi et al applied a PMITP to hydrogen doping on ZnO. 13,14 Their results showed that irradiation of the Ar-H 2 PMITP can dope hydrogen atoms into ZnO and thereby improve its photoluminescence. In addition, we have continued fundamental investigations to elucidate the unique dynamic behaviors of the PMITP using experimental and numerical approaches.…”