Improved performance of In(Ga)As/GaAs quantum dot solar cells via light scattering by nanoparticles

Abstract

InAs quantum dots have been used to extend the absorption edge of InGaAs/GaAs quantum well solar cells from 940 to ∼1100 nm. In order to improve absorption of infrared radiation by the thin (300 nm) active layer, we exploit its high refractive index, which acts as a waveguide for certain frequencies of light. Surface-deposited nanoparticles scatter incident radiation into waveguide modes of the devices, yielding improved infrared photocurrent generation of at least 10% at all wavelengths between 700 and 1100 nm, short-circuit current density increases of up to 16%, and corresponding gains in power conversion efficiency.