High Efficiencies in Gd ₂ Ru ₂ O ₇ Pyrochlore Oxide Photoanode‐Based Dye‐Sensitized Solar Cells Using Natural Dyes From <i>Anacardium</i> , <scp> <i>Baphia nitida</i> </scp> , and <i>Lannea kerstingii Barks</i>

ABSTRACT Natural dye‐sensitized solar cells (DSSC‐N), inspired by the principles of photosynthesis, represent a dynamic field of research aimed at developing sustainable, low‐cost photovoltaic technologies. Recent efforts have focused on optimizing key components, in particular dyes based on natural pigments and advanced photoanode materials, to improve energy conversion efficiency and extend device longevity. In this study, we investigated three natural dyes extracted from the bark of African plant species, rich in thermoresistant anthocyanins. Optical characterization revealed high absorbance in the visible range (360–700 nm) for each dye. The energy bandgaps for the dyes from * Anacardium occidentale * bark ( DyeA ), * Lannea kerstingii * bark ( DyeL ), and * Baphia nitida * bark ( DyeB ) were determined to be 1.82, 2.10, and 2.29 eV, respectively. Thermal degradation analysis showed that these dyes maintain stability up to 140°C. The DSSC‐Ns were fabricated with a nanostructured Gd 2 Ru 2 O 7 (GRO) photoanode, which exhibited a plasmonic effect to enhance photon absorption. Solar cells sensitized with DyeL, DyeA , and DyeB achieved conversion efficiencies of 10.18%, 10.13%, and 8.76%, respectively. Among these, DSSC‐N DyeL‐based cells demonstrated superior performance, with a fill factor (FF) of 65.49%, a short‐circuit current density ( J sc ) of 9.172 mA/cm 2 , and an open‐circuit voltage ( V oc ) of 1.694 V over an active area of 1.9 cm 2 . The integration of GRO plasmonic nanostructures with thermally stable phenolic compound‐based dyes presents a promising strategy for improving DSSC‐N device performance.