(333f) Reduced Graphene Oxide and Perovskites As Potential Electrodes for Biomolecular Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) with biomolecular photosensitizers interfaced with wide bandgap semiconductors enable enhanced electron excitation, injection, and dye neutralization for efficient photon-to-electron quantum-conversion. Here, a novel DSSC architecture is proposed and established via using pre-extracted, cost-effective, sustainable, and naturally-sensitized biomolecular pigment as carotenoids (-carotene). The proposed bio-DSSC structure involves: (1) photoanode as ITO/TiO₂/MAPbI₃/-carotene; (2) counter electrode (CE) or cathode as ITO/reduced graphene oxide (rGO); and (3) liquid electrolyte as iodide/triiodide [I^-/I₃^-] redox mediators; giving the cell architecture: [ITO/TiO₂/MAPBI₃/-carotene/[I^-/I₃^-]/rGO/ITO]. The wide bandgap semiconductor (TiO₂) accepts dye-sensitized photo-generated electrons in their conduction band for electron injection and charge separation at the [TiO₂+MAPbI₃]/dye interface. 3D organometal halide perovskites (MAPbI₃) with their conventional bandgap energy (1.55 eV) enhances visible-light absorption (380–700 nm) acting as a co-sensitizer. The hybrid dye-perovskite photoanode structure is believed to extend the photoanode light absorption spectrum (visible-IR: 300–1100 nm) and reduce interfacial recombination with the oxidized radicals. Raman spectrum and IV-probe/solar-simulator (AM 1.5) tools are used for materials characterization and light-to-electricity conversion evaluation, respectively. Anchoring carboxylic groups and conjugated double bonds in -carotene provide firm dye attachment and develop photosensitizer activity, respectively; hence, facilitating electron transfer. Similarly, utilization of a thin-coated rGO onto the CE is expected to improve current density owing to the reduced series resistance. Futuristically, there is a great potential towards integrating bio-derived photosensitized anodes in many photovoltaic and optoelectronic applications for commercial viability.