High-efficiency blue LEDs with thin AlGaN interlayers in InGaN/GaN MQWs grown on Si (111) substrates

摘要

We demonstrate high-efficiency blue light-emitting diodes (LEDs) with thin AlGaN interlayers in InGaN/GaN multi-quantum wells (MQWs) grown on Si (111) substrates. The peak external quantum efficiency (EQE) η_(EQE) of 82% at room temperature and the hot/cold factor (HCF) of 94% have been obtained by using the functional thin AlGaN interlayers in the MQWs in addition to reducing threading dislocation densities (TDDs) in the blue LEDs. An HCF is defined as η_(EQE)(85℃)/η_(EQE)(25℃). The blue LED structures were grown by metal-organic chemical vapor deposition on Si (111) substrates. The MQWs applied as an active layer have 8-pairs of InGaN/ALGa_(1-y)N/GaN (0