Influence of free carrier screening on the luminescence energy shift and carrier lifetime of InGaN quantum wells

Abstract

We studied the influence of free carrier screening on the luminescence energy shift and carrier lifetime of InGaN multiple quantum wells (MQWs) mainly in relation to a quantum-confined Stark effect. We performed a systematic time-resolved photoluminescence measurement of MQWs for various carrier densities and three different well widths (2.5, 4.0, and 5.5 nm). We show that the energy shift and the change in carrier lifetime are explained well by the free carrier screening effect which compensates for the internal electric field.

Solid-State Lighting Based on Light Emitting Diode Technology

“…Redshifts of emission energy and lower emission intensity were found in strained quantum wells based on III-nitrides, confirming the strong influence of the strain-induced piezoelectric field. However, with increasing carrier injection, a blue shift of the emission peak was observed by several researchers [33,34] and attributed to the reduction of the QCSE due to the in-well field screening by carriers. Therefore, in an LED structure, the electric field across the quantum wells is not only determined by the polarisation field but also affected by the carrier density and distribution in the quantum well region.…”

Internal quantum efficiency enhancement of GaInN/GaN quantum-well structures using Ag nanoparticles

“…When increasing the excitation power density, in addition to the increase in IQE, the GaInN/GaN QWs peak emission wavelength is blue-shifted due to the screening piezoelectric field by free-carriers. 31,32 For the reference sample the emission peak around 528 nm is red-shifted to 537 nm when the excitation power is decreased to 1 mW/cm 2 . Such a red-shift with decreasing excitation power is also present for samples A-C. For sample A this implies an emission peak shift towards the LSP resonance.…”

On the origin of the redshift in the emission wavelength of InGaN/GaN blue light emitting diodes grown with a higher temperature interlayer

“…Thus, the band filling effect is negligible and will not be considered in this case. 10 When the injection current increases, more free electrons and holes are generated, and this leads to a free-carrier-induced electric field to compensate with the piezoelectric field. Hence QCSE becomes smaller, the transition energy will become larger, and this causes a blue-shift of the emission peak wavelength.…”