Dependency of Light Extraction Efficiency on Sapphire Substrate Pattern Shapes in Light Emitting Diodes

질화물계 발광다이오드에서 광 추출 효율의 패턴 기판 의존성

The light extraction efficiencies of GaN-based light-emitting diodes (LEDs) grown on differently patterned sapphire substrates were investigated by using the ray tracing method. It was found that angle of the pattern surface against the sapphire surface, the number of pattern per unit area were important structural factors for high extraction efficiency.