Synergistic photovoltaic performance of DSSCs based on ZnO charge transport layers, counter electrodes and C. annuum and T. indica as natural dyes

Energy band diagram and experimental strategy for fabrication and investigating power conversion efficiency of 12 different DSSCs configurations. [Display omitted] •Al/Ni co-doped ZnO as charge transporting medium in DSSC for solar energy harvesting.•Seed extracts of Capsicum annuum and Tamarindus indica as natural photosensitizers.•12 DSSCs configurations comprised of working electrodes, dyes and counter electrodes.•Maximum 1.71 % PCE is for DSSC employing charge transport layer ZAN(SFM) and dye Capsicum annuum. Twelve Dye-Sensitized Solar Cells (DSSCs), in terms of three categories, were designed and fabricated employing ZnO-based charge-transport layers, Capsicum annuum (C. annuum) and Tamarindus indica (T. indica) as natural dyes and, Graphite and PEDOT:PSS as counter electrodes. J-V curves and cell efficiencies (η) of all DSSC combinations were measured. Among DSSCs in category-1 maximum and minimum η of 1.25% and 0.47% were estimated for FTO/ZAN37/C. annuum(dye)/HSE/Graphite and FTO/ZAN37/T. indica (dye)/HSE/Graphite, respectively. In the case of category-2, the DSSCs FTO/ZAN55/T. indica (dye)/HSE/PEDOT:PSS showed 0.60% efficiency and FTO/ZAN55/T. indica (dye)/HSE/Graphite revealed as high as η = 1.07%. Similarly, for category 3, the maximum η = 1.71% and minimum η = 0.32% were recorded for the DSSC’s combinations; FTO/ZAN(SFM)/C. annuum(dye)/HSE/Graphite and FTO/ZAN(SFM)/C. annuum(dye)/HSE/PEDOT:PSS. Based on charge transporting layers, dyes, and counter electrodes, a synergistic effect was developed in each considered DSSC led to a mechanism of the solar power conversion process.