Low-temperature photoluminescence study of exciton recombination in bulk GaAsBi

Abstract

The exciton recombination processes in a series of elastically strained GaAsBi epilayers are investigated by means of time-integrated and time-resolved photoluminescence at T = 10 K. The bismuth content in the samples was adjusted from 1.16% to 3.83%, as confirmed by high-resolution X-ray diffraction (HR-XRD). The results are well interpreted by carrier trapping and recombination mechanisms involving the Bi-related localized levels. Clear distinction between the localized and delocalized regime was observed in the spectral and temporal photoluminescence emission.

Automated numerical characterization of dilute semiconductors per comparison with luminescence

“…Mazzucato et al (2014), confirming the results found in Ref. Oriaku and Pereira (2017), the initial values for q; r; C ð Þ were 1E15; 2E À 3; 1 ½ .…”

“…Experimental data such as in Refs. Krier et al (2012) and Mazzucato et al (2014) provides the luminescence peak energy at different temperatures for InAsN. Thus, by applying the least squares method, we can estimate the parameters q; r; C ð Þ so that the residual between the theoretical function and the experimental data is minimized.…”

“…An interesting feature of dilute semiconductor material is the anomalous energy emission peaks at low temperatures, following an unusual s-shape behaviour that is associated with disorder and localization effects, which have been seen in both dilute bismides (Mazzucato et al 2014) and nitrides (Krier et al 2012). A simple and efficient method to describe this and other light emission effects in those materials is used here (Oriaku and Pereira 2017), based on analytical solutions for the Photon Green's functions approach Henneberger 1996, 1998;Michler et al 1998), delivering a microscopic, fully quantum mechanical solution.…”

Photoreflectance and photoluminescence study of localization effects in GaAsBi alloys

“…Similar PL results were found in GaAsN alloys when the excitation power was increased [41]. Recently, at low temperature, Mazzucato et al [32] have demonstrated clear distinction between the localized and delocalized states in the spectral and temporal photoluminescence emission. Indeed, at low excitation power, the localized emission is more pronounced.…”

“…Epitaxial layers of GaAsBi have demonstrated a reduced temperature dependence of the lasing wavelength, which makes them promising for the manufacture of laser diodes and semiconductor optical amplifiers that do not require Peltier cooling [10]. Recently, a large number of reports on detailed optical characterizations of GaAsBi were published [7,14,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. They include temperature dependence of PL, time-resolved PL, Photomodulated transmittance and photoreflectance (PR).…”