Thermal Characterization of UV LEDs
AlxGa1-xN (x>0.6) based Ultraviolet Light Emitting Diodes (UV LEDs) emit in the UV C range of 200 – 290 nm and suffer from low external quantum efficiencies. This leads to high device temperatures due to self-heating at the device junction. Knowledge of the device temperature is essential to implement appropriate thermal management techniques. In our work, we are using a variety of thermal metrology methods along with COMSOL FEA to quantify and model the temperature and stress distribution in UV LEDs. In addition, we have developed a modified version of the Thermal Resistance Analysis by Induced Transient (TRAIT) method to quantify the packaging resistance within the LED architecture.
Packaging of High Power LEDs
In this work, we are exploring the use of a number of packaging materials, thermal management techniques and developing models to package LED arrays to maximize heat dissipation. In addition, we are developing characterization methods to help understand the degradation seen in LEDs for solid state lighting technology.
Passive and Liquid Cooling
We are exploring both passive and liquid cooling of electronics including LED Systems. In this work, we are using unique molecular modifiers to change the surface wetting characteristics to enhance two phase heat transfer as well as the performance of heat pipes that are used in cooling electronics. Both super hydrophobic and super hydrophyllic surfaces have been created for used in these technologies.