Electroluminescence from the InGaN/GaN Superlattices Interlayer of Yellow LEDs with Large V-Pits Grown on Si(111)

A blue emission originated from In GaN/GaN superlattice(SL) interlayer is observed in the yellow LEDs with V-pits embedded in the quantum wells(QWs), revealing that sufficient holes have penetrated through the QWs into SLs far away from the p-type layer. In the V-pits embedded LEDs, hole transport has two paths: via the flat c-plane region or via the sidewalls of V-pits. It is proved that the holes in SLs are injected from the sidewalls of V-pits, and the transportation process is significantly affected by working temperature, current density, and the size of V-pits. Four motion possibilities are discussed when the holes flow via the sidewalls. All these may contribute to a better understanding of hole transport and device design.