Enriched visible light absorption by Au-embedded Sm3+ doped TiO2 compact photoanode for enhanced dye-sensitized solar cell performance

The cooperative effect of Samarium (Sm3+)-doped TiO2 and gold nanoparticles (Au NPs) is investigated in this work to explore its potential to boost visible light absorption in dye-sensitized solar cells (DSSC). As Sm3+ exhibits PL emissions at 583 nm, 612.2 nm, 663.6 nm, and 726.3 nm, there is an overlap with the absorption region of the N719 dye and these PL emission wavelengths resulting in a rise in photocurrent density and PCE owing better UV light harvesting. Sm3+ absorption and emissions were boosted by LSPR (Localized surface plasmon resonance) of Au NPs. As a result, the Au NPs embedded Sm-doped TiO2 photoanode-based DSSC capture more visible light. Sm (0.3)-TiO2 based DSSC reports the highest PCE (η:7.2%) among a series of Sm (0.2%, 0.3%, 0.4%, and 0.5% mol) TiO2 concentrations. Further, with the addition of Au NPs into the Sm3+ -doped TiO2, the PCE is enlarged into (η: 8.33%), which is more than 60% higher than TiO2 photoanode-based DSSC (η: 5.58%). •A comprehensive analysis on the increased performance of Samarium (Sm3+)-doped TiO2-based DSSC is discussed.•Sm (0.3%)-TiO2 possesses superior optical and electrical conductivity, as determined by several characterisation techniques. Sm3+ harvests UV-radiation via down-conversion, improving DSSC performance.•Extra energy has been captured by the LSPR effect and energy transfer events between Sm3+ energy states and Au NPCs with the introduction of Au NPs.•Au NPs embedded Sm (0.3% mol)-doped TiO2 based DSSC had a higher PCE(η) (8.3%) with 65% enhancement as compared to undoped-TiO2-DSSC.