Hybrid top transparent electrode for infrared-transparent bifacial perovskite solar cells

We present the design and fabrication of bifacial perovskite solar cells that possess remarkable transparency to infrared light. Our approach involves the incorporation of an oxide–metal–oxide structure-based hybrid top transparent electrode (TE) consisting of NiO/Ag/NiO (NAN). With feedback from optical modeling, NAN-TE was successfully fabricated with electrical sheet resistance as low as 5.04 Ω/sq, along with an average visible transmittance of ∼80%, using a low-energy adatom-based physical vapor deposition technique. Incorporating the fabricated TE in the device configuration of ITO/SnO2/MAPbI3/Sprio-OMeTAD/NAN, a power conversion efficiency (PCE) of 9.05% and 6.54% was achieved when illuminated from the ITO and NAN side, respectively, demonstrating a high bifacility factor of 72%. In comparison, an opaque device showed a PCE of 13.61%. The devices also showed high durability, retaining 80% of their initial PCE for over 1000 h without any encapsulation in ambient environmental conditions. The device also exhibited significantly high light transmission (∼40%) in the 800- to 1200-nm near-infrared region. Furthermore, our NAN-TE has a total thickness of <40 nm, making it a potential TE for various optoelectronic applications due to its carefully engineered optical design. The demonstrated NAN-TE has immense potential to achieve outstanding performance in building integrated photovoltaics and tandem applications.