Influence of Microstructure and Package Design on Heat Flow in Light-Emitting Diodes

Light emitting diodes (LED) have been wildly used in all kinds of flat panel display. Furthermore, LEDs are also extending their applications in daily illumination. In order to increase the light output power, distributed Bragg reflector (DBR) layers were usually applied into standard LED structure between multi-quantum well and substrate. However, heat flow in materials might be impeded by these micro-structures. This phenomenon will not only decrease the effective thermal conductivity but also increase the thermal resistance of the entire device. Furthermore, the difference of thermal resistance before and after package is also an important issue while solving the problems of thermal management. Therefore, in order to understand how micro-structure affects the heat flow inside LED structure, we are going to measure the temperature difference across DBR layers by using transient spectrum measurement. Besides, we will use transient-voltage method to observe and figure out the thermal resistance during package level. Hence, this project is not only valuable for thermal conduction engineering for high-power LEDs but also offers a brand new direction for combining nano-science and solid-state physics with industrial development.

Project ID:PB10001-0992
External Project ID:NSC99-2221-E182-034-MY2