Photoluminescence characterisation of InGaAs/GaAs quantum well structures

Abstract

A photoluminescence (PL) study of InGaAs/GaAs strained quantum well (aw) structures is reported. Both fully strained and partially relaxed structures are examined, and we show that carrier localisation in the latter leads to enhanced extrinsic luminescence.Two other sources of localisation are considered, namely alloy and interface fluctuations, and their effect on the PL spectra is discussed. The effect of indium concentration (xln) on the PL spectra is also examined, with greater surface roughening being observed at higher xln, in turn leading to wider PL linewidths. Finally, we have examined the effect of nonradiative recombination in these QWS. In the unrelaxed layers the trap density is shown to be very low, while non-radiative recombination in the partially relaxed layers most likely occurs at electrically active extended dislocations.

Experimental Study of Electronic Quantum Interference, Photonic Crystal Cavity, Photonic Band Edge Effects for Optical Amplification

“…The presence of GaAs-AlOx intermittent structure provides this design with the index contrast necessary to produce a photonic band gap in this system. A steam-based oxidation system has been found to produce AlOx with sufficient mechanical strength, lower stress and optical properties necessary for optical use [4]. …”

Peculiar Temperature-Power Dependence of AlGaAs/GaAs Multi Quantum Well

“…The strong dependence of MQW sample on temperature with its QW PL intensity quenched at different temperatures depending on QW thickness has been reported before. 15 that the higher energy lines from thinner QW quenched at lower temperatures, because of carrier thermal escape to the thicker QW. 10 It can be noted in Figure 3 that the QW of thickness 11.2 nm has a PL survived longer with temperature, which is attributed to exciton dissociation and excess flow of carrier to the QW.…”

Photoluminescence studies of strained CdTe/Cd0.633Mn0.367Te single quantum wells

“…The exciton trapping on the interface misfit dislocations can be excluded based on the slow decrease in luminescence intensity at low temperatures. 31,32 Since such quenching mechanism is not related to the quality of material but is an intrinsic property of the QWs, one must increase the confinement energy of the QWs by employing large manganese CdMnTe barrier layers to improve the de-vice operation, which is also the reason that we study CdTe/ CdMnTe SQWs with large manganese in this article.…”