Implications of redesigned, high-radiative-efficiency GaInP junctions on III-V multijunction concentrator solar cells

摘要

Nonradiative recombination in inverted GaInP junctionsudis dramatically reduced using a rear-heterojunction design rather than the more traditional thin-emitter homojunction design. When this GaInP junction design is included in inverted multijunction solar cells, the high radiative efficiency translates into both higher subcell voltage and high luminescence coupling to underlyingudsubcells, both of which contribute to improved performance.udSubcell voltages within two and four junction devices are measured by electroluminescence and the internal radiative efficiency is quantified as a function of recombination current using optical modeling. The performance of these concentrator multijunctionuddevices is compared with the Shockley–Queisser detailed-balance radiative limit, as well as an internal radiative limit, which considers the effects of the actual optical environment in which a perfect junction may exist.