Band gap renormalization and carrier localization effects in InGaN∕GaN quantum-wells light emitting diodes with Si doped barriers

Abstract

The optical properties of two kinds of InGaN∕GaN quantum-wells light emitting diodes, one of which was doped with Si in barriers while the other was not, are comparatively investigated using time-integrated photoluminescence and time-resolved photoluminescence techniques. The results clearly demonstrate the coexistence of the band gap renormalization and phase-space filling effect in the structures with Si doped barriers. It is surprisingly found that photogenerated carriers in the intentionally undoped structures decay nonexponentially, whereas carriers in the Si doped ones exhibit a well exponential time evolution. A new model developed by O. Rubel, S. D. Baranovskii, K. Hantke, J. D. Heber, J. Koch, P. Thomas, J. M. Marshall, W. Stolz, and W. H. Rühle [J. Optoelectron. Adv. Mater. 7, 115 (2005)] was used to simulate the decay curves of the photogenerated carriers in both structures, which enables us to determine the localization length of the photogenerated carriers in the structures. It is found that the Si doping in the barriers not only leads to remarkable many-body effects but also significantly affects the carrier recombination dynamics in InGaN∕GaN layered heterostructures.

Competition between confinement potential fluctuations and band-gap renormalization effects inIn0.53Ga0.47As/InDuarte1, Poças2, Laureto3 et al. 2008Phys. Rev. B9170View full textAdd to dashboardCite

“…[10][11][12][13][14] Experimental evidences of these phenomena were obtained from photoluminescence ͑PL͒ spectra of bulk materials and semiconductor heterostructures in samples with high doping levels 11,12 as well as at conditions of intense optical pumping, using pulsed 13 and continuous lasers. 14 The main characteristic of BGR is the observation of a redshift of the lower edge of the luminescence line and, generally, of the PL peak energy ͑E PL ͒ when there is an increase in the doping level or in the optical excitation intensity.…”

Violet Electroluminescence of AlInGaN–InGaN Multiquantum-Well Light-Emitting Diodes: Quantum-Confined Stark Effect and Heating Effect

“…The injection of high density of carriers can lead to the presence of band-filling effect. The spectral features for the bandfilling effect include the significant increase of the EL intensity at higher energy side and noticeable shift of the EL peak towards the higher energy side [5], [13], [18], as observed in Fig. 3.…”

“…High pure hydrogen gas was used as the carrier gas. Following a 3-m-thick n -GaN (Si: 5 10 cm ) bottom contact layer, three periods of undoped AlInGaN-InGaN QWs with 28-nm-thick barrier layers and 2-nm-thick well layers were grown. Then the top contact layer of 200-nm-thick p-GaN (Mg: cm ) was grown.…”

Improvement in threshold of InGaN∕GaN quantum-well lasers by p-type modulation doping

“…This phase space filling effect was observed in a recent experimental work. 22 The shapes of r sp are broader for Q v = 0.45 than those for Q v = 0.33 due to the larger contribution of r sp,cb for Q v = 0.45. For a shallower electron QW, the bound subband is closer to the continuous subbands.…”