High power light-emitting diode junction temperature determination from current-voltage characteristics

2008 ◽  
Vol 104 (9) ◽  
pp. 093104 ◽  
Author(s):  
A. Keppens ◽  
W. R. Ryckaert ◽  
G. Deconinck ◽  
P. Hanselaer
Keyword(s):  
High Power ◽  
Light Emitting Diode ◽  
Junction Temperature ◽  
Light Emitting ◽  
Temperature Determination ◽  
Current Voltage ◽  
Current Voltage Characteristics

Thermal Analysis of High Power Light Emitting Diodes Package

2011 ◽  
Vol 687 ◽  
pp. 215-221
Author(s):  
Yuan Yuan Han ◽  
Hong Guo ◽  
Xi Min Zhang ◽  
Fa Zhang Yin ◽  
Ke Chu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
High Power ◽  
Thermal Field ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Convective Heat Exchange ◽  
Input Power ◽  
Junction Temperature ◽  
Original Structure ◽  
Light Emitting

With increasing of the input power of the chips in light emitting diode (LED)， the thermal accumulation of LEDs package increases. Therefore solving the heat issue has become a precondition of high power LED application. In this paper, finite element method was used to analyze the thermal field of high power LEDs. The effect of the heatsink structure on the junction temperature was also investigated. The results show that the temperature of the chip is 95.8°C which is the highest, and it meets the requirement. The conductivity of each component affects the thermal resistance. Convective heat exchange is connected with the heat dissipation area. In the original structure of LEDs package the heat convected through the substrate is the highest, accounting for 92.58%. Three heatsinks with fin structure are designed to decrease the junction temperature of the LEDs package.

5mm × 5mm Sized Slug on High Power LED Stress and Junction Temperature Analysis

2013 ◽  
Vol 404 ◽  
pp. 460-464
Author(s):  
Zaliman Sauli ◽  
Vithyacharan Retnasamy ◽  
Fairul Afzal Ahmad Fuad ◽  
Phaklen Ehkan ◽  
Rajendaran Vairavan ◽  
...  
Keyword(s):  
High Power ◽  
Light Emitting Diode ◽  
Input Power ◽  
Junction Temperature ◽  
Temperature Analysis ◽  
Single Chip ◽  
Physical Size ◽  
Light Emitting ◽  
Simulation Results ◽  
Incandescent Lamps

Conventional incandescent lamps are being replaced by high power light emitting diode as a lighting source due to it ascendancy in terms of physical size, performance, output and lifetime. Nevertheless, the reliability and efficiency of the LED is dependent on the junction temperature. This study presents the thermal simulation of single chip LED package with 5mm x5mmx 1mm aluminum heat slug. The junction temperature and stress of LED chip were evaluated using Ansys version 11. Input power of 0.1 W and 1 W were applied to the LED. The simulation results showed that at input power of 1W, the maximum junction temperature and stress of the LED chip is 112.91°C and 263.82Mpa respectively.

Thermal Characteristics of High-Power LED Packages with Dissipation Film

2013 ◽  
Vol 397-400 ◽  
pp. 1767-1771
Author(s):  
Cheng Yi Hsu ◽  
Yu Li Lin
Keyword(s):  
High Power ◽  
Diamond Film ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Thermal Characteristics ◽  
Large Change ◽  
Junction Temperature ◽  
Conduction Model ◽  
Element Analysis ◽  
Light Emitting

A simple, fast, and reliable characterization method for measuring junction temperature (Tj) on high power GaN-based light emitting diodes (LED) was presented in this study. Thermal characteristics of high power Light-emitting-diode have been analyzed by using a three-dimensional thermal conduction model. Maximum operation temperature has also been calculated. The induced thermal behaviors of the best package processes for LED device with diamond film were investigated by finite element analysis (FEA) and by experimental measurement. The large change of forward operation voltage with temperature in light emitting diodes is advantageously used to measure junction temperature. Using this method, junction temperature (Tj) of LED under various structures and chip mounting methods was measured. It was found that the junction temperature can be reduced considerably by using diamond film substrates to replace sapphire substrate. In this study, the junction temperature can be decreased by about 14.3% under 1.5W power and decreased by about 15.9% under 1W power for 1mm square die. The thermal resistance (RT) can be measured to be 14.8°C/W under 1.5W power and 16.6°C/W under 1.W power.

Numerical Analysis for Thermal Performance of High Power Multi-Chip LED Packaging

2010 ◽  
Vol 139-141 ◽  
pp. 1433-1437
Author(s):  
Kai Lin Pan ◽  
Jiao Pin Wang ◽  
Jing Liu ◽  
Guo Tao Ren
Keyword(s):  
High Power ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Three Dimensional ◽  
Junction Temperature ◽  
Light Emitting ◽  
Die Attach ◽  
Dissipation Model ◽  
Key Issues

Heat dissipation and cost are the key issues for light-emitting diode (LED) packaging. In this paper, based on the thermal resistance network model of LED packaging, three-dimensional heat dissipation model of high power multi-chip LED packaging is developed and analyzed with the application of finite element method. Temperature distributions of the current multi-chip LED packaging model are investigated systematically under the different materials of the chip substrate, die attach, and/or different structures of the heat sink and fin. The results show that the junction temperature can be decreased effectively by increasing the height of the heat sink, the width of the fin, and the thermal conductivity of the chip substrate and die attach materials. The lower cost and higher reliability for LED source can be obtained through reasonable selection of materials and structure parameters of the LED lighting system.

Tetraphenylmethane-Based 1,3,4-Oxadiazole as Electron Transporting Materials in Organic Light-Emitting Devices

1999 ◽  
Vol 598 ◽  
Author(s):  
Chin-Ti Chen ◽  
Tzu-Yao J. Lin ◽  
Hsiu-Chih Yeh ◽  
Li-Hsin Jan ◽  
Easwaramoorthy Balasubramaniam ◽  
...  
Keyword(s):  
Glass Phase ◽  
Molecular Design ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Current Voltage ◽  
Electron Transporting Layer ◽  
Current Voltage Characteristics

ABSTRACTA series of tetrahedral tetramers of 2,5-diphenyl substituted 1,3,4-oxadiazole compounds were synthesized and characterized for electron-transporting layer (ETL) in organic light-emitting diode (OLED). The multiple-branch design of the oxadiazole tetramers intends to increase the melting temperature and to generate glass phase of the low molar mass derivative such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD). We observed temperatures of the glass phase transition for the oxadiazole tetramer with appropriate peripheral substituents, indicative of amorphous characteristics of the molecule in spite of highly symmetrical molecular framework. The luminescence-current-voltage characteristics of multilayer OLED devices containing the oxadiazole tetramer or PBD as ETL were examined to evaluate the efficiency of our multiple-branch molecular design.

scholarly journals Efficiency and Droop Improvement in GaN-Based High-Voltage Flip Chip LEDs

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yen-Chih Chiang ◽  
Bing-Cheng Lin ◽  
Kuo-Ju Chen ◽  
Sheng-Huan Chiu ◽  
Chien-Chung Lin ◽  
...  
Keyword(s):  
High Voltage ◽  
Flip Chip ◽  
Light Emitting Diode ◽  
Bragg Reflector ◽  
Light Extraction ◽  
Efficiency Enhancement ◽  
Distributed Bragg Reflector ◽  
Light Emitting ◽  
Current Voltage ◽  
Current Voltage Characteristics

The GaN-based high-voltage flip chip light-emitting diode (HVFC-LED) is designed and developed for the purpose of efficiency enhancement. In our design, the distributed Bragg reflector (DBR) is deposited at the bonded substrate to increase the light extraction. After the flip chip process, the general current-voltage characteristics between the flip chip sample and the traditional sample are essentially the same. With the help of great thermal conductive silicon substrate and the bottom DBR, the HVFC-LED is able to enhance the power by 37.1% when compared to the traditional high-voltage LEDs. The wall-plug efficiencies of the HVFC-LED also show good droop reduction as high as 9.9% compared to the traditional devices.

Para-sexiphenyl-CdSe Nanocrystals Hybrid Light Emitting Diodes with Optimized Layer Thickness and Interfaces

2009 ◽  
Vol 1154 ◽  
Author(s):  
Clemens Simbrunner ◽  
Gerardo Hernandez-Sosa ◽  
Eugen Baumgartner ◽  
Günter Hesser ◽  
Jürgen Roither ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Spectral Response ◽  
Cdse Nanocrystals ◽  
Device Performance ◽  
Leakage Currents ◽  
Light Emitting ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
High Color Purity ◽  
Narrow Emission

AbstractCdSe/ZnS nanocrystals are embedded in para-sexiphenyl (p-6P) based hybrid light emitting diode devices providing red, green and blue (RGB) emission compatible to the HDTV color triangle. By structural and optical investigations the device parameters are optimized. The device performance is analyzed in respect to electrical and spectral response resulting in current-voltage characteristics with small leakage currents and low onset voltages. Furthermore the devices provide high color purity and stability which is demonstrated by their narrow emission line widths. All these results underline the ability of the presented device configuration to act as a future candidate for display applications.

Electrical Behavior I-V Theoretical-Experimental OLEDS

2014 ◽  
Vol 1613 ◽  
pp. 121-126
Author(s):  
José M. Burgoa ◽  
Cecilia González-Medina ◽  
Ramón Gómez-Aguilar ◽  
Jaime Ortiz-López
Keyword(s):  
Light Emitting Diode ◽  
Hole Injection ◽  
Software Environment ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Current Voltage ◽  
Polymer Semiconductor ◽  
Current Voltage Characteristics ◽  
Derivatives Of ◽  
Magnitude Difference

ABSTRACTWe develop a program (within MATLAB software environment) to numerically simulate current-voltage characteristics of a bilayer organic light-emitting diode (OLED). The program is based on the Poole-Frenkel and Schottky continuous quantum models which take into account the geometry of thin films and their emission parameters in the calculation of charge carrier and current density in organic materials. Simulations are performed for OLEDs with A/EML/C and A/HIL/EML/C architectures where A=anode, HIL=hole injection layer, EML=emissive layer and C=cathode. For EML we assume MEH-PPV and MDMO-PPV derivatives of poly-para-phenylene-vinylene (PPV) polymer semiconductor, and for HIL we use PEDOT:PSS. The results of simulation are compared with experimental results obtained from actual OLED devices constructed in our laboratory. For comparison we also use the commercial software SimOLED to simulate the devices under similar architectures. We find in general a fair agreement between the simulated and measured behavior except for a few orders of magnitude difference in the current.

Sign in / Sign up

Export Citation Format

Share Document