Plasmonic Au NPs embedded Ytterbium-doped TiO2 nanocomposites photoanodes for efficient indoor photovoltaic devices

• The work demonstrates efficient photoanodes incorporating gold (Au) nanoparticle NPCs embedded into Ytterbium (Yb) doped TiO 2 NWs for indoor photovoltaic applications. • Yb-doped TiO 2 nanoparticles showed a reduction in the rutile phase, and the nanowire's structures completely exempted the rutile phase from the mixed composition, revealed via XRD analysis. • UPS analysis reveals that the formation of oxygen vacancies and Ti 3+ -states resulting from Yb-doping into TiO 2 may improve the electron hopping mechanism. • The extended absorption edge, enhanced dye adsorption capabilities, and the increased dielectric constant of Yb-doped TiO 2 NW indicate that it possesses superior optoelectronic features. In addition, PL studies reveal improved charge transportation and injection abilities. • The highest PCE% was achieved by a DSSC constructed with Au NPCs embedded in Yb-doped TiO 2 NW, with a PCE% enhancement of 40% in outdoor lighting (1 sun) and more than 50% under indoor lighting (1000 LUX). Herein, we present an all-inclusive investigation on the effect of plasmonic gold nanoparticles (Au NPCs) embedded Yb-doped TiO 2 nanostructured photoanode for efficient photovoltaics devices. Optimally doped Yb (0.5 mol%)-TiO 2 nanoparticles (NPCs) were synthesised by solid-state grinding. Their structural, morphological, optical, and surface properties were evaluated using XRD, Raman spectroscopy, SEM-EDX, UPS, and XPS. Results show that Yb-doped TiO 2 NPCs form, reducing the rutile phase and shifting the fermi level. After demonstrating the enhanced properties of Yb-doped TiO 2 NPCs, we introduced single anatase phase nanowire structures for comparison. Dielectric measurements show Yb-doped TiO 2 NW's higher conductivity. Plasmon-induced enhancement of light absorption is achieved by implanting Au NPCs into Yb-doped TiO 2 NW for additional light harvesting. As a proof of concept, optimised Yb-doped TiO 2 photoanode DSSC were fabricated and tested under the AM1.5, 1 sun illumination exhibiting photoconversion efficiency (PCE) of 6%. Devices employing Yb-doped TiO 2 NW: Au NPCs photoanode exhibited Jsc to 18.8 % mA-cm -2 and PCE% to 8%. Under white LED (1000 LUX) exhibited PCE of 13.9% for Au/Yb-TiO 2 NW photoanode. The electrochemical impedance spectroscopy (EIS) measurements on these devices established the Yb-doped TiO 2 NW: Au NPCs photoanode based device exhibited the lowest charge transport resistance (R2:86Ω) and charge recombination resistance (R3:20Ω) which are consistent with the J-V characteristics suggesting the potential use of these photoanode for indoor photovoltaics and in general any devices for allied energy and environmental areas of research.