FABRICATION, CHARACTERIZATION AND APPLICATIONS OF AlInGaN LIGHT-EMITTING DIODES

摘要

We address several key issues associated with developing power AlInGaN light-emitting diodes (LEDs). Chip design is optimized in terms of current spreading, light extraction and scalability. P-type metallization with desirable electrical and optical properties is developed. Based on the improved design and processing, high-flux AlInGaN LEDs with a flipchip configuration have been demonstrated. The flipchip LEDs exhibit a 50% increase in light extraction compared to the conventional top-emitting devices. The correlations between the LED characteristics and material structural properties, such as high dislocation density and large indium segregation, are studied. The mechanisms of carrier injection, localization and recombination in commercial green, blue and UV LEDs are discussed. Finally the current state-of-the-art and key remaining challenges regarding the use of AlInGaN LEDs for general lighting applications are reviewed.