Excitation intensity dependence of photoluminescence in Ga0.52In0.48P

Abstract

The excitation intensity dependence of the photoluminescence (PL) from Ga0.52In0.48P grown by organometallic vapor phase epitaxy on GaAs substrates has been investigated as a function of epitaxial layer growth temperature and substrate orientation. It is well known that the degree of ordering and the band-gap energy of this material are functions of growth conditions. We report here on a PL emission which shifts rapidly with excitation intensity. The rate of emission shift is also a function of growth conditions including substrate orientation. There is, however, no significant correlation between the band-gap energy and the rate of emission shift in Ga0.52In0.48P. This PL shift is explained in terms of band filling of potential fluctuations that are associated with a microstructure consisting of ordered domains within a disordered matrix.

Optical properties of InAlAs/GaAsSb heterostructures grown by metalorganic vapor phase epitaxy

“…[11][12][13][14] Our observed value of 8.3 meV is larger than the values of ␤ found by Yu et al, 10 where the band gap fluctuations are caused by local strain relaxation. The shift of the quasi-D-A transition peak is however in line with that observed due to ordering in Ga 0.52 In 0.48 P. 17 It is not clear why the D-A transition peak is observed as a separate, lower-energy peak in sample C and not in sample B ͑see Fig. 1 inset͒.…”

Homogeneous linewidths of excitons in high and low band gap Ga0.52In0.48P

“…1 b) than for sample H (Fig. l a ) and has been attributed to state filling of lower-lying 3 4-k1 localized states [6]. Very recently, Ernst et al [21] have argued that the spatial region separating distinct partially ordered domains is the origin for the low-energetic PL peak.…”

“…The partially ordered alloy rather consists of domains with varying degrees of order. More specifically, mixtures of more-ordered GalnP domains (lower band gap material) with less-ordered domains (higher band gap material) are commonly assumed to account for the characteristic PL and transport behavior [6,11 to 151. The optical band gap of such ordered domains depends on the degree of order and the domain size [6].…”

“…More specifically, mixtures of more-ordered GalnP domains (lower band gap material) with less-ordered domains (higher band gap material) are commonly assumed to account for the characteristic PL and transport behavior [6,11 to 151. The optical band gap of such ordered domains depends on the degree of order and the domain size [6]. Accordingly, the statistical distributions of domain sizes and band gaps should contribute to or even dominate the inhomogeneous broadening of excitonic resonances in partially ordered GaInP.…”

Optical properties of highly disordered InGaP by solid-source molecular beam epitaxy with a GaP decomposition source

“…However, InGaP grown on GaAs presents a classic example of spontaneous atomic ordering in semiconductor alloys due to the differences of atomic sizes and bonding energies of InP and GaP [6,7]. Ordered InGaP shows many significantly differences of optical properties: photoluminescence (PL) emission energy (presumably band gap) reduces, emission spectrum becomes broad [8], there are two or more peaks in PL spectra, PL peak shows blue shifts with increasing excitation intensity and anomalous temperature dependence, and so on [9][10][11]. Band-gap reduction limits the applications of InGaP, such as in shorter wavelength ranges.…”