Strain effects on radiation tolerance of quantum dot solar cells

A comparison of quantum dot (QD) triple junction solar cells (TJSCs) under tensile strain are compared to those under compressive strain and baseline devices to examine the effects of strain induced by the QD layers. It is found that tensile strain leads to degradation of i-region material at values of -706 ppm. Irradiating with 1 MeV electrons triple junction solar cells with tensile strain exhibit a faster degradation in I_sc of the QD samples and slower degradation in V_oc but overall faster degradation in efficiency compared to baseline TJSCs, regardless of the magnitude of tensile strain. Compressively strain QD TJSCs have similar degradation in I_sc and slower degradation in V_oc compared to baseline TJSCs. From this study it is determined a strain of +400 ppm in the QD superlattice allows for the best performance pre- and post- irradiation for QD TJSCs based upon AM0 IV and quantum efficiency.