Investigation of parasitic absorption and charge carrier recombination losses in plasmonic silicon solar cells using quantum efficiency and impedance spectroscopy

Quantum efficiency and impedance spectroscopy tools are employed for understanding the influence of parasitic absorption losses and partial field effect surface passivation by the silver nanoparticles (Ag NPs) on electrical properties of textured silicon solar cells without and with Si3N4 spacer layer. The parasitic absorption losses from Ag NPs reduced the internal quantum efficiency near the surface plasmon resonance region. The passive components like; series and parallel resistances, chemical capacitance of solar cells without and with Ag NPs are estimated after fitting impedance semicircles, which are further used for estimating effective carrier lifetime (τeff) values. Under AM1.5G illumination, cells with Si3N4 spacer layer showed a large decrease in the τeff due to the strong parasitic absorption losses from the Ag NPs. But, the cells without Si3N4 spacer layer showed a small decrease in the τeff due to the reduced surface recombination after partial field effect passivation from near-fields of Ag NPs’ surface plasmon resonances on the emitter surface.