Improved performance of InGaAs/GaAs quantum dot solar cells using Si-modulation doping

N-type silicon modulation doping was introduced into the barrier layers of InGaAs/GaAs quantum dot solar cells (QDSC) at two different doping concentrations. An increased energy conversion efficiency of 8.91 % was obtained for the modulation doped device compared to 6.95 % of the undoped sample due to the additional electron population in the active structure.