High Temperature Characterizations for GaN-based LED Devices
Student: Camara Johnson
Major Professor: Dr. Zhong Chen
Research Area(s):
Microelectronics
Microelectronics & Nanoscience and Engineering
Background/Relevance
- LEDs are manufactured in a way that the cooler the environment, the higher the light output will be.
- Commercial LEDs that are currently on the market can only withstand temperature up to 425K (~150°C), and uses bulky heat sink to bring down the temperature to get high efficiency.
- GaN-based LEDs however can withstand higher temperatures (>650K) which makes them more ideal.
Innovation
- GaN LEDs will be used in power modules to control circuits for harsh environment applications such as: space applications, automotive industry, deep drilling machines, petroleum excavation, etc.
Approach
- High temperature vacuum test environment is created using MMR hall effect chamber.
- Bias the LED with different forward biased current and collect light output using a Spectrometer.
- Repeat the measurements for different temperatures varying from room temperature to 475 K.
- Study the changes in peak wavelength and intensity at high temperatures.
Key Results
- High temperature testing proved that GaN LEDs can withstand high temperature without efficiency droop.
- Collected data shows that the intensity of peak wavelength decreases with temperature as expected.
Conclusions
- GaN LEDs provide improved performance over traditional LEDs for applications requiring high temperatures; more experiments needed.
