Low Forward Voltage III-Nitride Red Micro-Light-Emitting Diodes on a Strain Relaxed Template with an InGaN Decomposition Layer

In this study, III-nitride red micro-light-emitting diodes (mu LEDs) with ultralow forward voltage are demonstrated on a strain relaxed template. The forward voltage ranges between 2.00 V and 2.05 V at 20 A/cm(2) for device dimensions from 5 x 5 to 100 x 100 mu m(2). The mu LEDs emit at 692 nm at 5 A/cm(2) and 637 nm at 100 A/cm(2), corresponding to a blueshift of 55 nm due to the screening of the internal electric field in the quantum wells. The maximum external quantum efficiency and wall-plug efficiency of mu LEDs are 0.31% and 0.21%, respectively. This suggests that efficient III-nitride red mu LEDs can be realized with further material optimizations.