Photoluminescence close to V-shaped pits in the quantum wells and enhanced output power for InGaN light emitting diode

Unlike the typical 'S-shaped' temperature dependent behavior for InGaN/GaN light emitting diodes (LEDs), the emission of the c-plane MQWs (C-QWs) close to V-shaped pits (V-pits) broadens across the short-wavelength band and exhibits a blue-shift as temperature increases by temperature-dependent micro photoluminescence (mu-TDPL). The phenomenon can be mainly attributed to a higher proportion carriers generate high-energy radiative transition in C-QWs close to V-pits because of augmented carrier mobility, in which the mechanism of carriers absorbed in sidewall MQWs (S-QWs) move to the C-QWs close to V-pits acts as a significant process. The sizes of V-pits can be enlarged as increasing the thickness of low temperature GaN interlayer (LT-GaN interlayer), leading to improved output power for LEDs.