High-Power, Low-Efficiency-Droop Semipolar (20\bar{2}\bar{1}) Single-Quantum-Well Blue Light-Emitting Diodes

Reduction in Thermal Droop Using Thick Single-Quantum-Well Structure in Semipolar (20\bar{2}\bar{1}) Blue Light-Emitting Diodes

We report on the thermal performance of the electroluminescence of 12-nm-thick single-quantum-well (SQW) InGaN blue light-emitting diodes (LEDs) grown on the semipolar (20 2 1) plane. At a current density 100A/cm, the external quantum efficiency (EQE) decreased by 9.7% when the temperature was increased from 20 to 100 C. Hot/cold factors were more than 0.9 at current densities greater than 20A/...

High-Efficiency Single-Quantum-Well Green and Yellow-Green Light-Emitting Diodes on Semipolar (20\bar{2}1) GaN Substrates

We demonstrate high-efficiency green and yellow-green single-quantum-well light-emitting diodes (LEDs) grown on semipolar (20 21) GaN substrates by metal organic chemical vapor deposition. The output power and external quantum efficiency at a driving current of 20mA under a pulsed condition with a 10% duty cycle are 9.9mW and 20.4% for the green LED and 5.7mW and 12.6% for the yellow-green LED,...

Analysis of low efficiency droop of semipolar InGaN quantum well light-emitting diodes by modified rate equation with weak phase-space filling effect

High optical power and low-efficiency droop blue light-emitting diodes using compositionally step-graded InGaN barrier

ELECT A compositionally step-graded (CSG) InGaN barrier is designed for the active region of c-plane blue light-emitting diodes (LEDs). High external quantum efficiencies of 45, 42, 39 and 36% are achieved at current densities of 100, 200, 300 and 400 A/cm, respectively. Compared with GaN barrier devices, LEDs with CSG InGaN barriers showed higher power, lower operating voltage and smaller wave...

Blue light emitting diode exceeding 100 % quantum efficiency

1 Introduction GaN-based light-emitting diodes (LEDs) deliver the desired high efficiency only at relatively low injection current density [1]. At the elevated current densities required in practical high-brightness applications , the efficiency is substantially reduced. This efficiency droop phenomenon has been intensely investigated for a number of years, but the physical mechanisms behind it...