DSSCs: a facile and low-cost MgSnO₃-based transparent conductive oxides via nebulized spray pyrolysis technique

The primary focus of this investigation was constructing worthwhile and cost-effective TCO substrate to make low-cost dye-sensitized solar cells entirely. Magnesium tin oxide substrates were prepared at a substrate temperature of 400 °C via nebulizer spray pyrolysis approach with different molar ratios of magnesium and tin (S1–0.1 M:0.4 M and S2–0.1 M:0.5 M) precursors. The annealing temperature was kept at 400 °C for three hours. While analyzing the properties of the prepared substrates, the following results were obtained. The thickness of the prepared samples for S1 and S2 increases from 0.47 to 0.56 μm, respectively. From the XRD results, the prepared samples were rhombohedral inistructure, and the grain size was found to be 31 (S1) and 40 (S2) nm. From the observations of optical studies, the percentage of transmission exceeds 80% and corresponding band-gap values were found to be 3.59 eV (S1) and 3.66 eV (S2). From Hall voltage measurement, it was noted that MgSnO₃ shows n-type conductivity. The resistivity value was observed to be low of the order of 10^–4 Ω cm which was closer to the resistivity of existing commercially available TCO substrates (for FTO: ~ 7 to ~ 10 Ω cm and for ITO: ~ 8 to ~ 12 Ω cm). FESEM results ensure that the prepared films were leaf-like structures. EDAX analysis shows that the atomic percentage of required elements (Mg, Sn, O) present in the prepared samples. The FTIR analysis ensures the appearance of hydroxyl and water functional groups owing to atmospheric water vapors and the chemical bonding in MgO and MgO–SnO. DSSC’s was fabricated with different combinations of FTO/MTO photoanodes and counter electrodes and the efficiency of the cells has been compared. The maximum efficiency of 3.95% was obtained for the fabricated DSSC using MTO as a substrate for photoanode and counter electrodes which was higher than that of other combinations of FTO/MTO substrates.