A Numerical Model for Studying Multimicrochip and Single-Chip LEDs With an Interdigitated Mesa Geometry

Abstract

A 3-D numerical model has been developed to investigate the transient thermal, electrical, and optical output performance of a single-chip light-emitting diode (LED) with an interdigitated mesa geometry under dc operation and a multimicrochip LED under either dc or full-wave operation. These two LED chips are fabricated on the same sapphire wafer. The junction temperature, the light output power, and the electroluminescence intensity of both LEDs are measured under dc to prove the results of the numerical simulations. The numerical simulation results are in good agreement with the experimental ones. The numerical results indicate that the multimicrochip LED under dc operation will demonstrate the best thermal and light output performance. Utilizing the input power considered in the present computation, the light output power for the multimicrochip LED, under either dc or full-wave operation, is raised continuously. On the other hand, the saturation of the light output is observed for the single-chip LED with interdigitated mesa geometry.

Keywords

• Full-wave
• high-voltage light-emitting diodes (HV LED)
• junction temperature
• multimicrochip