The investigation explores the fabrication and characteristics of ZnO nanowire (NW)/p-GaN/ZnO NW heterojunction light-emitting diodes (LEDs). Vertically aligned ZnO NWs arrays were grown on the p-GaN substrate. The n-p-n heterojunction LED was fabricated by combining indium tin oxide/glass substrate with the prepared ZnO NWs/p-GaN substrate. The symmetrical rectifying behavior demonstrates that the heterostructure herein was formed with two p-n junction diodes and connected back to back. The room-temperature electroluminescent emission peak at 415 nm was attributed to the band offset at the interface between n-ZnO and p-GaN and defect-related emission from ZnO and GaN. Finally, the photograph indicated the LED clearly emitted blue light.

In this study, the growth of high-density single-crystalline ZnO nanowires on patterned ZnO:Ga/ SiO₂/Si templates was reported. We also adsorbed Au onto nanowire surfaces and fabricated ZnO nanowire acetone vapor sensors. With 200-ppm acetone vapor concentration, it was found that we could enhance the device sensitivities at 300deg C from 18.5% to 82.5% by Au adsorption. It was also found that measured responses at 300degC were around 52%, 61%, 71%, 77%, and 82% when the accumulative acetone vapor concentration reached 5, 10, 50, 100, and 200 ppm, respectively, for the ZnO nanowire sensor with Au adsorption.

Vertically well-aligned ZnO nanowire ultraviolet (UV) photodetectors were fabricated by spin-on-glass technology on ZnO:Ga/glass templates. With $2\mathrm{V}$ applied bias, it was found that dark current density of the fabricated device was only $2.0\times {10}^{-7}\mathrm{A}∕{\mathrm{cm}}^2$ . It was also found that UV-to-visible rejection ratio and quantum efficiency of the fabricated ZnO nanowire photodetectors were more than 1000 and 12.6%, respectively.

We report the fabrication of a lateral ZnO nanowire UV photodetector on a glass substrate using tungsten as the growth barrier to suppress the vertical growth of the ZnO nanowires. Upon UV illumination, the detector current increased by more than 1 order of magnitude. Furthermore, the noise equivalent power and the normalized detectivity <mml:math display="inline"><mml:mrow><mml:msup><mml:mi>D</mml:mi><mml:mo>∗</mml:mo></mml:msup></mml:mrow></mml:math>D∗ of the fabricated lateral ZnO nanowire photodetector were <mml:math display="inline"><mml:mrow><mml:mn>7.89</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mrow><mml:mn>10</mml:mn></mml:mrow><mml:mrow><mml:mo>−</mml:mo><mml:mn>11</mml:mn></mml:mrow></mml:msup><mml:mspace width="0.5em"></mml:mspace><mml:mi mathvariant="normal">W</mml:mi></mml:mrow></mml:math>7.89×10−11W and <mml:math display="inline"><mml:mrow><mml:mn>1.9</mml:mn><mml:mo>×</mml:mo><mml:msup><mml:mrow><mml:mn>10</mml:mn></mml:mrow><mml:mrow><mml:mn>8</mml:mn></mml:mrow></mml:msup><mml:mspace width="0.5em"></mml:mspace><mml:mtext>cm</mml:mtext><mml:mspace width="0.5em"></mml:mspace><mml:msup><mml:mrow><mml:mtext>Hz</mml:mtext></mml:mrow><mml:mrow><mml:mn>0.5</mml:mn></mml:mrow></mml:msup><mml:mspace width="0.5em"></mml:mspace><mml:msup><mml:mi mathvariant="normal">W</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>1.9×108cmHz0.5W−1 , respectively.