Irradiation Effects in Space Solar Cells Made of Multiple Absorbers

Abstract

Solar cells made of multiple absorbers are a commonly used approach for improving efficiency due to their extended range of spectral sensitivity. Indeed, efficiencies nearing the theoretical maximum have been achieved with a triple-junction device made of Ino. 5 ,Gao. 49 P (InGaP 2 ), GaAs, and Ge solar cells connected in series. For extraterrestrial applications, there is the added requirement of radiation tolerance. The main challenge for space power-generation is therefore the development of highly efficient and radiation-tolerant devices. We have investigated several aspects of the radiation response of solar cells made of multiple absorbers, such as multijunction devices and quantum-well solar cells. Novel possibilities such as quantumdot solar cells and ordered-disordered heterostructures are proposed.

High-efficiency metamorphic GaInP/GaInAs/Ge solar cells grown by MOVPE

“…Fig. 4 shows a comparison of EBIC and CL images taken on four separate 8%-In and 1%-In samples each from the same wafer from two sequential growth runs [13]. At the beam conditions used, the EBIC image is from approximately 400 nm deep into the sample and the CL image is approximately 700 nm deep into the sample.…”