Effect of growth temperature and quantum structure on InAs/GaAs quantum dot solar cell.

InGaAs-capped InAs quantum dots (QDs) and InAs QDs were adopted for the study of the effects through growth temperature and the band structure of InAs QDs on the performance of GaAs-based QD solar cell. It has been shown that the defects due to low temperature growth resulted in the decrease of Voc, Jsc and external quantum efficiency for GaAs bulk solar cell and QD embedded solar cells. It has been also found that InAs QDs act as defects by trapping photo-generated carries which affect the carrier transport in QD solar cell. The QD solar cell with InGaAs-capped InAs QDs showed higher performance than the QD solar cell with only InAs QDs. Such result has been explained by photo-generated carrier trapping and tunneling through InGaAs QW state in InGaAs-capped InAs QDs.