Junction temperature rise due to self-heating effects in GaInN blue light-emitting diodes

2017 ◽  
Vol 641 ◽  
pp. 8-11 ◽  
Author(s):  
Se Joon Oh ◽  
Jaehee Cho
Keyword(s):  
Blue Light ◽  
Temperature Rise ◽  
Light Emitting Diodes ◽  
Junction Temperature ◽  
Light Emitting ◽  
Self Heating ◽  
Heating Effects

Self-heating effects at high pump currents in deep ultraviolet light-emitting diodes at 324 nm

2002 ◽  
Vol 81 (18) ◽  
pp. 3491-3493 ◽  
Author(s):  
A. Chitnis ◽  
J. Sun ◽  
V. Mandavilli ◽  
R. Pachipulusu ◽  
S. Wu ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Self Heating ◽  
Heating Effects ◽  
High Pump ◽  
Deep Ultraviolet ◽  
Ultraviolet Light Emitting Diodes

Study the Effect of Junction Temperature on the Peak Wavelength in GaN-Based High-Power Green Light Emitting Diodes

2011 ◽  
Vol 399-401 ◽  
pp. 1034-1038
Author(s):  
Rong Rong Zhuang ◽  
Ping Cai ◽  
Jiang Li Huang
Keyword(s):  
High Power ◽  
Temperature Rise ◽  
Light Emitting Diodes ◽  
Green Light ◽  
Red Shift ◽  
Junction Temperature ◽  
Spectral Peak ◽  
Peak Wavelength ◽  
Drive Current ◽  
Light Emitting

The junction temperature of GaN-based high-power green light emitting diodes is measured using the temperature coefficients of the diode forward voltage, from changes in temperature and changes in drive current to measure the LED junction temperature and the corresponding spectral, Respectively. Experiments show that, junction temperature due to environmental temperature increased, and the red shift of the spectral peak wavelength. When low temperature or less then the rated current range, the drive current increased in junction temperature rise due to the spectral peak wavelength blue shift . When the current is increased in the range of close to or greater than the rated current, leading to the junction temperature rise will cause spectral red shift . The peak wavelengths’ shift degree of 0.0579nm / k, 0.0751 nm / k and-0.1974nm / k, -0.0915 nm / k are calculated in both cases. The phenomenon is due to the LED junction temperature increases lead to band gap shrinkage, and the result of the role of spontaneous polarization and piezoelectric polarization in Ⅲ-nitride semiconductor materials.

Micro-Raman Spectroscopy: Self-Heating Effects In Deep UV Light Emitting Diodes

2002 ◽  
Vol 743 ◽  
Author(s):  
A. Sarua ◽  
M. Kuball ◽  
M. J. Uren ◽  
A. Chitnis ◽  
J. P. Zhang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Heat Dissipation ◽  
Light Emitting Diodes ◽  
Light Output ◽  
Multiple Quantum ◽  
Light Emitting ◽  
Self Heating ◽  
Micro Raman Spectroscopy ◽  
Heating Effects ◽  
Heat Sinking

ABSTRACTUltraviolet light emitting diodes (LED) based on GaN and its ternary alloy AlGaN are key devices for applications such as solid state white lighting and chemical sensing. Ultraviolet LEDs are prone to self-heating effects, i.e., temperature rises during operation, contributing significantly to the commonly observed saturation of light output power at relatively low input currents. Rather little, however, is known about the actual device temperature of an operating ultraviolet LED. Using micro-Raman spectroscopy temperature measurements were performed as a function of input current on 325nm-Al0.18Ga0.82N/Al0.12Ga0.88N multiple quantum wells LEDs grown on sapphire substrates, flip-chip mounted on SiC for heat-sinking. Temperature maps were recorded over the active device area. Temperature rises of about 65 °C were measured at input currents as low as 50mA (at 8V) for 200 μm x 200 μm size LEDs despite flipchip mounting the devices. Temperature rises at the device edges were found to be higher than in the device center, due to combined heat sinking and current crowding effects. Finite difference heat dissipation simulations were performed and compared to the experimental results.

A Technique for the Direct Measurement of the Junction Temperature in Power Light Emitting Diodes

2020 ◽  
pp. 1-1
Author(s):  
Demetrio Iero ◽  
Massimo Merenda ◽  
Sonia Polimeni ◽  
Riccardo Carotenuto ◽  
Francesco G. Della Corte
Keyword(s):  
Direct Measurement ◽  
Light Emitting Diodes ◽  
Junction Temperature ◽  
Light Emitting

Blue light-emitting diodes in hair regrowth: the first prospective study

2021 ◽  
Author(s):  
G. Lodi ◽  
M. Sannino ◽  
G. Cannarozzo ◽  
A. Giudice ◽  
E. Del Duca ◽  
...  
Keyword(s):  
Prospective Study ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Hair Regrowth

scholarly journals Air stable and highly efficient Bi3+-doped Cs2SnCl6 for blue light-emitting diodes

RSC Advances ◽  
2021 ◽  
Vol 11 (42) ◽  
pp. 26415-26420
Author(s):  
Yue Yao ◽  
Si-Wei Zhang ◽  
Zijian Liu ◽  
Chun-Yun Wang ◽  
Ping Liu ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Color Coordinates ◽  
Blue Led ◽  
Highly Efficient ◽  
Photoluminescence Quantum Yield ◽  
Long Life

A Bi3+-doped Cs2SnCl6 exhibits photoluminescence at around 456 nm and a photoluminescence quantum yield of 31%. The blue LED based on the Bi3+-doped Cs2SnCl6 phosphor exhibits a long life of 120 hours and a CIE color coordinates of (0.14, 0.11).

scholarly journals Device Modeling of Quantum Dot–Organic Light Emitting Diodes for High Green Color Purity

2021 ◽  
Vol 11 (6) ◽  
pp. 2828
Author(s):  
Byoung-Seong Jeong
Keyword(s):  
Quantum Dot ◽  
Emission Spectrum ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Color Purity ◽  
Wavelength Band ◽  
Light Emitting ◽  
Green Color ◽  
Organic Light

In this study, the optimal structure for obtaining high green color purity was investigated by modeling quantum dot (QD)–organic light-emitting diodes (OLED). It was found that even if the green quantum dot (G-QD) density in the G-QD layer was 30%, the full width at half maximum (FWHM) in the green wavelength band could be minimized to achieve a sharp emission spectrum, but it was difficult to completely block the blue light leakage with the G-QD layer alone. This blue light leakage problem was solved by stacking a green color filter (G-CF) layer on top of the G-QD layer. When G-CF thickness 5 μm was stacked, blue light leakage was blocked completely, and the FWHM of the emission spectrum in the green wavelength band was minimized, resulting in high green color purity. It is expected that the overall color gamut of QD-OLED can be improved by optimizing the device that shows such excellent green color purity.

Sign in / Sign up

Export Citation Format

Share Document