The improvement of the light extraction efficiency (LEE) of a conventional InGaN blue light‐emitting diode (LED) by the incorporation of one‐dimensional ZnO sub‐microrods is reported. The LEE is improved by 31% through the wave‐guiding effect of ZnO sub‐microrods compared to LEDs without the sub‐microrods. Different types of ZnO microrods/sub‐microrods are produced using a simple non‐catalytic wet chemical growth method at a low temperature (90 °C) on an indium‐tin‐oxide (ITO) top contact layer with no seed layer. The crystal morphologies of needle‐like or flat‐top hexagonal structures, and the ZnO microrods/sub‐microrod density and size are easily modified by controlling the pH value and growth time. The wave‐guiding phenomenon within the ZnO rods is observed using confocal scanning electroluminescence microscopy and micro‐electroluminescence spectra.

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A new volcano-shaped patterned sapphire substrate (VPSS), which enhances the light extraction efficiency (LEE) of GaN-based light emitting diodes (LEDs), was presented. The Monte Carlo ray-tracing method shows that the VPSS with a crater slope angle of about 50 has the highest LEE. To compare the optical characteristics, 380 nm ultraviolet LEDs were grown on an optimized VPSS, hemispherical PSS (HPSS), and planar sapphire substrate by metal-organic chemical vapor deposition (MOCVD). As a result, the extraction efficiency of the LED grown on the optimized VPSS was estimated to be almost 2.8 times larger than that of the planar sapphire substrate and was enhanced 1.6 times compared with that of the LED grown on the HPSS. #

All-solution-processed transparent thin film transistors (TTFTs) are demonstrated with silver grid source/drain electrodes, which are fabricated by printing and subsequent silver nanoparticles solution coating, which allows continuous processing without using high vacuum systems. The silver grid electrode shows a reasonable transmittance in visible range, moderate electrical conductance and mechanical strength. The TTFTs are employed to drive liquid crystal cells and demonstrate a successful switching operation.

We report on the fabrication and characteristics of light-emitting diodes ͑LEDs͒ which consist of antimony ͑Sb͒ doped p-ZnO, ͑InGaN/GaN͒ multiquantum well ͑MQW͒, and n-GaN. An electroluminescence ͑EL͒ emission at a wavelength of 468 nm is observed from the hybrid LEDs after thermal annealing at 750°C, showing that Sb-doped p-ZnO can be used as a hole supplying layer in hybrid LEDs. Furthermore, the EL peaks are redshifted as the injection current is increased, indicating that the compressive strain in MQW layers is relaxed due to Sb-doped p-ZnO layer.