Carrier collection in quantum dots solar cells with barrier modification

InAs quantum dot (QD) has been attractive in high conversion efficiency solar cell applications, due to its extended absorption in the infrared spectrum and as a promising material for the intermediate band solar cell (IBSC). To enhance the sequential absorption process towards the concept of IBSC, modified barriers of InGaP were applied to suppress thermal escape and tunneling process in InAs quantum dots solar cells (QDSCs). Despite improved spectral response from QD absorption, InAs QDSC with InGaP barrier is associated with degradation in the bulk spectral response at room temperature; the carrier collection can be optimized via adjusting operation condition and solar cell design.