Current Spreading Analysis in Vertical Electrode GaN-based Blue LEDs

摘要

In this study, effects of n-electrode patterns to the current spreading in the active region were analyzed on the blue vertical light emitting diode (VLED) with GaN/InGaN multi quantum well (MQW). Several n-electrode patterns of the VLED are designed, analyzed qualitatively, and investigated its effect to current spreading in the active region. A 3-dimensinal circuit model whose parameters are experimentally extracted from an actual VLED chip is adopted for the quantitative analysis of current spreading. The n-electrode patterns are modeled and simulated by simple electrical circuits in order to find the current distribution and current-voltage characteristics of devices. Based on theoretical analysis results, blue VLEDs with different n-electrode patterns were fabricated and a series of measurements were carried out. Analytic and experimental results for different n-electrode pattern showed quite similar tendencies. Finally, we proposed some design methodologies for improved current spreading.