Electrical and optical interconnection for mechanically stacked multi-junction solar cells mediated by metal nanoparticle arrays

An interconnection approach for mechanical stacking of solar cells is described. In this approach, block copolymer-templated fabrication of metal nanoparticle arrays and van der Waals bonding were integrated to design interfaces which permit both high interfacial conductivities and minimal transmission losses upon interconnections of solar cells. A series of electrical and optical characterizations verified that the approach potentially provides resistances of as low as 3.7 Ω-cm2 with transmission losses of less than 2%. The demonstrative two-junction solar cell exhibited promising open-circuit voltage and fill factor, suggesting the possibility of achieving high-efficiency multi-junction solar cells based on this unique strategy.