The superior low-efficiency droop performance of semipolar (2021) InGaN light-emitting diodes (LEDs) makes it a hot candidate for efficient solid-state lighting and full-color displays. To unveil the mystery of this low droop and high efficiency, the emission dynamics of semipolar (2021) LEDs is investigated by time-resolved and steady-state photoluminescence (PL) measurements. Much smaller carrier lifetimes (radiative and nonradiative lifetime) were obtained from semipolar (2021) InGaN QWs compared with those on the -plane samples, possibly due to the reduced quantum-confined Stark effects and smaller indium fluctuation on semipolar InGaN samples. The experimental findings indicate a much reduced excess carrier density in semipolar (2021) InGaN LEDs, which will impact the device performance. Based on this, a modified ABC equation with weak phase-space-filling (PSF) effect was used to model the droop characteristics of semipolar (2021) LEDs.
- Efficiency droop
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering