Investigation of type-II Ga(As)Sb/GaAs quantum dots embedded in an InGaAs quantum well for solar cell applications

• Published in: Solid state communications Vol. 366-367; p. 115160
• Main Authors: Neffati, R., Hamrita, A., Yahyaoui, M., Boujdaria, K., Alshehri, Naif Ahmed
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2023
• Subjects: Computer modeling and simulation; Ga(As)Sb/GaAs quantum dots; Radiative lifetime; Radiative lifetime; 74.25.Gz; Ga(As)Sb/GaAs quantum dots; Computer modeling and simulation; 07.05.Tp; 73.21.La; 02.60.Cb
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/j.ssc.2023.115160

We theoretically investigate the electronic and optical properties of charge carriers in type-II Ga(As)Sb/GaAs quantum dots (QDs) embedded in an InGaAs quantum well (QW), to determine their viability for use in intermediate band solar cell (IBSC) devices. This hybrid structure has the advantage of allowing a large flexibility to alter wave function distribution of the electron ground state, which is often considered as an intermediate band (IB) in QD-IBSC. The polarized transitions dipole moment (TDM), the polarized absorption coefficients and the radiative lifetime were studied as a function of QD height. Our theoretical results show an enhancement of inter-band absorption spectrum with a redshift of the peak corresponding to h0→IB transition and a blueshift of the continuum→IB peak, as the height of QD increases. The intra-band light absorption spectrum exhibits a redshift and its magnitude remains almost unchanged, as the height of QD increases. Furthermore this structure provides strong intra-band light absorption comparable to that of type-I QDs and equivalent to h0→IB transition strength. A long carrier lifetime in IB of about 30ns was found, but remains more than an order of magnitude less than the inter-band radiative time due to the low confinement potentials of the electron along the ρ-axis in this type-II dot-in-well (DWELL) structure. •Optical properties of charge carriers in type-II Ga(As)Sb/GaAs quantum dots (QDs) embedded in an InGaAs quantum well (QW).•Intermediate band solar cell (IBSC) devices.•The polarized transitions dipole moment.