Device physics of nanoscale interdigitated solar cells

Recently there has been theoretical and experimental evidence for the formation of nanodomains in polycrystalline Cu(In,Ga)Se2 that may form complex three-dimensional intertwined p-n networks. This has caused some researchers to consider such a network as the operative method of current collection in Cu(In,Ga)Se2 solar cells. Quantitative modeling is required to test this assumption and evaluate the relevant physics. This paper uses multidimensional device simulation to explore the physics and solar cell performance of interdigitated p-n junctions for material parameters relevant to the postulated conditions. The physics at the nanoscale are often not intuitive, but the results indicate that interdigitated junctions can improve solar cell performance relative to corresponding planar-junction devices and achieve reasonably high solar cell efficiencies with semiconductor materials that have less than optimal electro-optical properties.