Experimental examination of an InAs/GaAs(Sb)/AlAsSb quantum dot approach to the intermediate band solar cell

In this study work towards an InAs/AlAs_0.56Sb_0.44 quantum dot (QD) prototype intermediate band solar cell(IBSC) grown on InP is presented. InAs QDs are suspended in an AlAs_0.56Sb_0.44/GaAs matrix in the unintentionally doped (uid) region of an In_0.52Al_0.48As solar cell are compared to a bulk In_0.52Al_0.48As solar cell. While addition of the InAs/AlAsSb matrix results in a drastic drop in AM1.5G performance, electroluminescence shows a peak shift from 855nm to 1623nm and spectral responsivity shows a similar absorption edge shift. A proposed design improvement uses an AlAs_0.56Sb_0.44 emitter to remove the injection barrier created by the use of AlAs_0.56Sb_0.44 in the uid-region.