The investigation of InGaAs quantum dot growth peculiarities for GaAs intermediate band solar cells

Abstract

In this work the growth peculiarities of InGaAs quantum dots (QDs) on GaAs surface have been investigated by metal-organic vapor-phase epitaxy (MOVPE). The influence of the main structural parameters, such as the amount of deposited InGaAs material and the thickness of the GaAs cap layer, on the optical properties of QDs has been considered. For these parameters the optimal values at which achieved the best photoluminescence intensity of QDs embedded into the matrix of the GaAs-based light-emitting structure have been established. The possibility of using several layers of QDs with the preservation of the optical properties of the investigated structures has been demonstrated. The design of solar cell (SC) based on GaAs with QD arrays in the active area has been proposed. It was shown that 20 layers of QDs embedded into the proposed SC structure contribute to the photogenerated current up to 0.97 mA/cm2 for AM0 spectra and up to 0.77 mA/cm2 for AM1.5D spectra, while maintaining the high quality of the p-n junction.