Photoluminescence properties of a Si doped InGaAs/InGaAlAs superlattice

Abstract

In this paper, the optical properties of a Si doped In 0.53 Ga 0.47 As/In 0.52 Ga 0.24 Al 0.24 As superlattice (SL) are investigated by using the photoluminescence (PL) technique in the temperature range of 9-300 K. The origins of the optical transitions observed in the spectra are attributed through the analysis of the transition behaviour with temperature and excitation power. The linewidths obtained at 9 and 300 K are smaller than those previously reported in the literature, and the blueshift observed with increasing temperature has a small magnitude, indicating the excellent quality of the sample. The experimental results are compared with theoretical calculations based on the envelope function formalism, with an excellent accordance. The excitonic emission was obtained in the range of 9-300 K, and the applicability of the Varshni, Viña, and Pässler (p-type and ρ-type) models, usually used to describe the variation of the excitonic energy transition as a function of temperature in semiconductor materials, was also analysed.

Exciton behavior in GaAs/AlGaAs coupled double quantum wells with interface disorder

“…Except for the curve obtained for P 3 , the energies of the PL peaks move to higher values with increasing temperature, up to a temperature T M (see Table 1). This blueshift with increasing temperature is well known [16,[18][19][20][21] and is attributed to the potential fluctuations in the regions where the excitonic recombination occurs. In the case of peak P 3 , the redshift observed at very low temperatures can be explained by the existence of more intense potential fluctuations in the regions associated with this recombination channel, which generate local minima and an absolute minimum in the confinement potential [16,19].…”

“…At low temperatures and low excitation powers, the PL spectra of the CDQWs can be accurately fitted by four Gaussian peaks, which were denoted by P 1 , P 2 , P 3 , and P 4 . This procedure has already been used in other studies [14,21,26] and it was shown to be appropriate for this kind of spectral analysis (see, for example, Ref. [14, p.…”

“…Although the DE associated with peak P 3 is smaller than that obtained for peak P 4 (see Table 1), the temperature at which its maximum blueshift occurs is relatively larger. This is due to the competition between two effects that occur as the temperature increases: (i) the blueshift of the PL peak, resulting from the filling of the band-tail states [16,[18][19][20][21], and (ii) the redshift of the PL peak, due to the electron-phonon interaction and the lattice thermal expansion [36,37]. As the potential fluctuations associated with peak P 3 are more intense, its maximum blueshift is observed at a higher temperature, at which the effects that cause the redshift are more intense, resulting in a smaller DE for this channel.…”

“…This subject has been recently studied in a great variety of semiconductor heterostructures made by several materials, such as GaAs/InGaP [16], InGaAs/AlAsSb [17], InGaAs/InAlAs [18], GaInNAs/GaAs [19], and InGaAs/InGaAlAs [20,21]. In single quantum wells (SQW) two or more lines related to the same quantum level have already been observed in the emission spectrum, which can be accounted for the bimodal interface roughness model [22][23][24][25].…”