Partial Polarization Matching in GaInN-Based Multiple Quantum Well Blue LEDs Using Ternary GaInN Barriers for a Reduced Efficiency Droop

Abstract

GaInN-based multiple-quantum-well (MQW) blue LEDs with ternary GaInN barriers polarization-matched to GaInN wells are fabricated. Single-layered Ga0.9In0.1N and Ga0.9In0.1N/GaN multiple-layered quantum barriers (MLQBs) are used for 50% polarization matching. Compared to conventional GaInN/GaN MQW LEDs, the polarization-matched LED with GaInN/GaN MLQBs shows a higher light output power in a high injection current regime, resulting in reduced efficiency droop, along with a minimal blue-shift of emission with injection current, reduced ideality factor, and reduced forward voltage. These results are attributed to a reduced magnitude of polarization sheet charges at heterointerfaces between the GaInN well and the GaInN barrier, and the resultant reduced internal polarization field in the MQWs, thereby minimizing electron leakage current and efficiency droop.