Light Efficiency Enhancement of Deep Ultraviolet Light-Emitting Diodes Packaged by Nanostructured Silica Glass

To enhance the light efficiency of deep ultraviolet light-emitting diodes (DUV-LEDs), a novel method was proposed through introducing tailored nanostructures on the surfaces of silica glass in the packaging process. The nanostructures were fabricated by using self-assembled gold nanoparticles by rapid thermal annealing (RTA) and additional dry etching. The temperature and the dwelling time of RTA process were investigated to obtain the nanostructures with the optimized feature sizes of ~100 nm for the DUV application. By utilizing the dual-side nanostructures, the average transmittance of the glass increases from 90.1% to 97.2% in the UV range and is less dependent on the incidence angle. Meanwhile, the light efficiency of DUV-LEDs packaged by the dual-side nanostructured glass is increased by 8.6% compared with that of the flat glass at the current of 50 mA.

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