InAs quantum dots on GaAs for intermediate band solar cells

Quantum dot intermediate band solar cells (QD-IBSC) have been produced in order to pave the road to high efficiency solar cells, demonstrating sub-bandgap absorption. Even though the obtained figures of merit are still lower than those of the samples without the quantum dots, optical activity of the nanostructures has been demonstrated. While the photovoltaic activity of the QD-IBSC is observed for wavelengths until 1000 nm, it vanishes at around 900 nm for the reference sample. We conclude that improvement in the QD morphological structure is still needed to minimize surface recombination and that more layers and a higher QD density is mandatory to increase the overall sub-bandgap absorption. Finally, a potential change in the solar cell growth conditions is suggested.