Ultra-thin dielectric-metal-dielectric as metal electrode alternative for bifacial perovskite and organic solar cells

Abstract

Third-generation solar cells have garnered significant attention for their potential in building-integrated photovoltaics (BIPV), driving the need for advanced electrode materials that combine optical transparency with electrical conductivity. Here, the development and integration of an ultrathin dielectric/metal/dielectric (DMD) structure as a transparent electrode for bifacial perovskite and organic solar cells is reported. The optimised DMD configuration, consisting of a 2 nm bottom dielectric layer, a 6 nm metal core, and a 2 nm top dielectric layer, achieves an optimal balance of high electrical conductivity (∼8 Ω/□) and average transmittance in the visible wavelength range (∼69 %), enabling efficient charge extraction while supporting back-illumination. Comprehensive characterisation of the DMD electrode—including optical, morphological, and electrical analyses—demonstrates its superior stability and functionality under thermal and mechanical stresses. Device-level performance evaluations revealed bifaciality factors of 65 % and 42 % for perovskite and organic solar cells, respectively, with peak power conversion efficiencies of 13.02 % for perovskite and 7.61 % for organic configurations. External quantum efficiency for back and front illumination has opened up interesting insights into the carrier dynamics of the devices. Capacitance studies further elucidated the charge transport dynamics and device quality under bifacial operation. These findings position DMD electrodes as a promising alternative to conventional metal contacts, offering a scalable pathway to durable, high-performance bifacial solar cells for next-generation photovoltaic technologies and sustainable energy applications.