Effect of Barrier Thickness and Barrier Doping on the Properties of InGaN/GaN Multiple‐Quantum‐Well Structure Light Emitting Diode

Optical and electrical properties of InGaN/GaN multi-quantum-well (MQW) structure light-emitting diodes (LED) are systematically studied as a function of barrier thickness and Si doping of barriers. The emission energy of photoluminescence (PL) and electroluminescence (EL) of MQW-LEDs decrease with barrier thickness increased, but with Si doping of barriers decreased. The electrical characteristics of MQW-LEDs strongly depend on barrier thickness and Si-doped content in barriers. With increasing barrier thickness, forward voltages of MQW-LEDs dramatically reduce as well as the barriers are increasingly doped with Si. Reverse currents of MQW-LEDs measured at reverse bias 6 V present a similar behavior that Ir increase with increasing barrier thickness as well as increasing Si doped content in barriers. The experimental results imply an optimized quality of MQW-LED fabrication by an appropriate combination of barrier thickness and carrier concentration.