Full spectrum ultrahigh efficiency photovoltaics

Abstract

Future photovoltaic systems can be greatly benefited by modules that exhibit simultaneously ultrahigh efficiency (> 50%) and low-cost (< $0.50/Wp) to enable sharp reductions in the levelized cost of electricity. A 'full spectrum' photovoltaic module, which takes advantage of advances in low-cost III-V compound cell fabrication and emerging optical and electronic fabrication/assembly methods, features 6-15 independently connected subcells in a spectrum splitting, concentrating photovoltaic receiver. Module architectures utilizing independently connected single junction and multijunction subcells allow flexibility in subcell selection for optimal energy bandgaps and fabrication, and also reduce the constraints posed by current matching requirements. Several different spectrum-splitting optical architectures designed for systems with many (>6) subcells are possible, including designs based on holographic spectrum splitting, specular reflection in dielectric polyhedra and light trapping textured filtered dielectric slabs that perform as nonimaging concentrators.