Quantum-confined Stark effect on photoluminescence and electroluminescence characteristics of InGaN-based light-emitting diodes

Abstract

The quantum-confined Stark effect (QCSE) on InGaN-based light-emitting diodes (LEDs) was investigated as a part of the continuing study of exploring differences between photoluminescence (PL) and electroluminescence (EL) characteristics. The luminescence characteristics were related to electrical characteristics of green and amber LEDs by employing the electrical-bias-applied PL technique. By inspecting the band diagram, it has been found that the separation of quasi-Fermi levels, which strongly affects the QCSE, can be quantified and related to the luminescence. In order to compare PL and EL characteristics, attention was paid to the QCSE during the PL and EL measurements. Despite the control of the QCSE, differences were still confirmed between PL and EL characteristics, which have led us to the conclusion to that there are other unrevealed origins for the differences.

Bias dependence and correlation of the cathodoluminescence and electron beam induced current from an InGaN/GaN light emitting diode

“…Carrier recombination and transport in LEDs are also strongly influenced by the applied electric field, both across the whole depletion region in the form of carrier overshoot and capture [10][11][12][13] and also in the quantum wells themselves via tunneling 13,14 and the quantum-confined Stark effect (QCSE). 15 Consequently, the applied voltage greatly affects the intensity and spectral characteristics of the CL spectrum as well as the EBIC. Both drift (Eq.…”

Semipolar GaN-based laser diodes for Gbit/s white lighting communication: devices to systems

“…LDs grown on c-plane GaN suffer from polarization-induced electric fields, leading to shifted electron and hole wave-functions. 23,24 Also, a high density of states (DOS) due to the balanced biaxial in-plane strain causes relatively high threshold current densities. Semipolar and nonpolar LDs have been predicted to have higher optical gain than c-plane LDs due to a higher wave-function overlap, a reduction in the density of states via separation of the three valence bands and natural dipole emission.…”

Effect of the barrier growth mode on the luminescence and conductivity micron scale uniformity of InGaN light emitting diodes

“…forward voltage across the p/n junction due to excess carriers reducing the size of the depletion region 16,21 and the magnitude of this effect may vary from device to device. These plots indicate that the four samples fall into two "families": those where there is no temperature ramp between quantum well and quantum barrier growth (1 T and Q2T) and those where there is a temperature ramp after barrier growth (2 T and T-bounce).…”