Enhanced performance of InGaN light-emitting diodes with InGaN/GaN superlattice and graded-composition InGaN/GaN superlattice interlayers



The advantages of InGaN-based light-emitting diodes (LEDs) with InGaN/GaN supperlattice (SL) and graded-composition InGaN/GaN SL interlayers in the last-barrier/EBL space are studied numerically. The electrostatic field, energy band diagrams, carrier concentrations, radiative recombination rate, light–current–voltage (LIV) performances, and internal quantum efficiency (IQE) are investigated. Simulation results show that the light-output power and IQE are both enhanced compared to the conventional LED due to the appropriately modified energy band diagrams, which are favorable for the improvement in hole injection efficiency and electron blocking capability, especially for the LED with graded-composition InGaN/GaN SL interlayer.