Light output improvement of InGaN ultraviolet light-emitting diodes by using wet-etched stripe-patterned sapphire substrates

2007 ◽  
Vol 102 (8) ◽  
pp. 084503 ◽  
Author(s):  
Chang-Chi Pan ◽  
Chi-Hsun Hsieh ◽  
Chih-Wei Lin ◽  
Jen-Inn Chyi
Keyword(s):  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Light Output ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Ultraviolet Light Emitting Diodes ◽  
Patterned Sapphire Substrates

AlGaN-Based Deep Ultraviolet Light-Emitting Diodes Fabricated on Patterned Sapphire Substrates

2011 ◽  
Vol 4 (9) ◽  
pp. 092102 ◽  
Author(s):  
Myunghee Kim ◽  
Takehiko Fujita ◽  
Shinya Fukahori ◽  
Tetsuhiko Inazu ◽  
Cyril Pernot ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Deep Ultraviolet ◽  
Ultraviolet Light Emitting Diodes ◽  
Patterned Sapphire Substrates

InGaN-based 405 nm near-ultraviolet light emitting diodes on pillar patterned sapphire substrates

CrystEngComm ◽  
2010 ◽  
Vol 12 (10) ◽  
pp. 3152 ◽  
Author(s):  
Pekka T. Törmä ◽  
Muhammad Ali ◽  
Olli Svensk ◽  
Sami Suihkonen ◽  
Markku Sopanen ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Near Ultraviolet ◽  
Ultraviolet Light Emitting Diodes ◽  
Patterned Sapphire Substrates

scholarly journals Improving Optical Performance of Ultraviolet Light-Emitting Diodes by Incorporating Boron Nitride Nanoparticles

Electronics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 835 ◽  
Author(s):  
Caiman Yan ◽  
Qiliang Zhao ◽  
Jiasheng Li ◽  
Xinrui Ding ◽  
Yong Tang ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Light Output ◽  
Light Emitting ◽  
Air Interface ◽  
Red Led ◽  
Boron Nitride Nanoparticles ◽  
Optical Flux ◽  
Ultraviolet Light Emitting Diodes

Ultraviolet light-emitting diodes (UVLED) are a new type of device in the LED development; however, the radiant efficacy of UVLEDs is still too low to satisfy the requirements of applications. In this study, boron nitride nanoparticles (BN NPs) are incorporated into the UVLED’s silicone encapsulation to improve the optical output power. This BN NPs-based package shows an increase in optical flux of 8.1% compared with silicone-only encapsulation when the BN NP concentration is optimized at 0.025 wt%. By analyzing the BN NP film, adding the BN NPs into silicone leads to a decrease in transmittance but an increase in haze. Haze and transmittance has an excellent negative correlation with increasing BN concentration under 365 nm. The moderate BN NP concentration maximizes the scattering performance from haze while maintaining high transmittance. Therefore, this enhanced light output is attributed to scattering that reduces optical losses from total internal reflection at the silicone–air interface. By using the new BN-based structure in green and red quantum dot devices, an increase radiant flux of the device is observed, 9.9% for green LED and 11.4% for red LED. This indicates that BN NPs have potential prospects in the application of UV LEDs used as excitation sources for quantum dots.

scholarly journals Nanostructural Effect of ZnO on Light Extraction Efficiency of Near-Ultraviolet Light-Emitting Diodes

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Young Jae Park ◽  
Hyounsuk Song ◽  
Kang Bok Ko ◽  
Beo Deul Ryu ◽  
Tran Viet Cuong ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Indium Tin Oxide ◽  
Light Emitting Diodes ◽  
Light Output ◽  
Light Extraction Efficiency ◽  
Zno Nanostructures ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Output Efficiency ◽  
Ultraviolet Light Emitting Diodes

The effect of ZnO nanostructures on the light output power of 375 nm near-ultraviolet light-emitting diodes (NUV-LEDs) was investigated by comparing one-dimensional (1D) nanorods (NR-ZnO) with two-dimensional (2D) nanosheets (NS-ZnO). ZnO nanostructures were grown on a planar indium tin oxide (ITO) by solution based method at low temperature of 90°C without degradation of the forward voltage. At an injection current of 100 mA, the light output efficiency of NUV-LED with NR-ZnO was enhanced by around 30% compared to the conventional NUV-LEDs without ZnO nanostructures. This improvement is due to the formation of a surface texturing, resulting in a larger escape cone and a multiple scattering for the photons in the NUV-LED, whereas the light output efficiency of NUV-LED with NS-ZnO was lower than that of the conventional NUV-LEDs due to the internal reflection and light absorption in the defective sites of NS-ZnO.

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