AlGaInAs quantum dot solar cells: Tailoring quantum dots for intermediate band formation
We report on the realization of quantum dot (QD) solar cells comprising a spectrally large absorption range. The QD absorption band is designed by integrating quaternary AlGaInAs QDs with varying aluminum contents in combination with conventional InAs/GaAs QDs in the intrinsic region of an AlGaAs p-i-n structure. By adjusting the material composition in the different QD layers, we can cover a spectral range from 680 to 1150 nm by QD absorption. Based on our results we discuss a newly proposed solar cell design employable to facilitate intermediate band absorption for an increased efficiency.