The Environmental Performance at Low Intensity, Low Temperature (LILT) of High Efficiency Triple Junction Solar Cells

A number of JPL missions, either active or in the p l d g stages, require the accurate LILT flew intensity low temperatme) clmracte* of tripk-jumtbn solar, Although triple ignetiOn LILT pwloraaanee was reported as recently as 2002, there has been an evolutionary advance in cell technology by both U.S. space cell manufacturers that, for mission design pnrposes, effectively obde&% the earlier data As a dt, JPL MWed a program to develop a database for the LILT performauce of tbe new high performance t s p k jMction sdnr eel4 apL obtained Emcore Advanced Triple J t i O a CIC assemblies and Spectrdab Ultra Triple JuactiOn CIC assemblies. 'These cells were tested at temperature-intensity ranges designed to cover applicatioas between 1 and 5.18 AU solar distances. 1 MeV deetron irradiatks from 25 E14 to 1 El5 w m performed on the d s to evaluate the COBdbiaed effect ol particulde radirdion m d LILT coQdiitio1l8, The e $ k t of IlLT conditions was OBServed to igcnr aq htcrerrse m the variptioe of d l pdomances tBpt at shula4ed 5.18 AU eonditkms the average perfonhance was approximately 3dY0 with the best cells measuring between 32 and 34% efficiency. The 30Ye average efficiency compares with appmximately BY0 average efffifiiency measured on earlier tahobgy