Researchers from the Singapore-HUJ Alliance for Research and Enterprise (SHARE) and Nanyang Technological University have developed semi-transparent perovskite solar cells with over 13% efficiency and 27% transparency using plasmonic Au nanorods.
Semitransparent hybrid perovskites can open the door to applications in smart windows and building-integrated photovoltaics (BIPV). One route towards semitransparency is thinning the perovskite film, which has several benefits like cost efficiency and reduction of lead. However, this tends to result in reduced light absorbance. To compromise this loss, it is possible to incorporate plasmonic metal nanostructures, which can trap incident light and locally amplify the electromagnetic field around the resonance peaks.
In this work, the team used Au nanorods (NRs), which are not detrimental for the perovskite and whose resonance peak overlaps with the perovskite band gap. The Au NRs were deposited on top of a thin (200 nm) semitransparent perovskite film.
These semitransparent perovskite solar cells with 27% average visible transparency reportedly show enhancement in the open-circuit voltage (Voc) and fill factor, demonstrating 13.7% efficiency (improved by ∼6% compared to reference cells).
Furthermore, Au NR implementation enhances the stability of the solar cell under ambient conditions. These findings demonstrate the ability to compensate for the light harvesting of semitransparent perovskites using the plasmonic effect.