Boosting the Performance of Monolithic Dye-Sensitized Solar Cells under Simulated Solar and Artificial Light

The expected increase in the global Internet of Things market in the next decades demands the development of low-cost low-environmental impact power supplies; it was within this framework that indoor photovoltaics (iPVs) is emerging. Copper-mediated monolithic dye-sensitized solar cells (M-DSSCs) are among the most promising choices for iPVs since they combine high photovoltaic performance with low-cost and simple production, the use of abundant and safe materials, and pleasing aesthetics. Herein, M-DSSCs were fully optimized, targeting maximizing the power conversion efficiency (PCE) under simulated AM1.5G and 600–1000 lx indoor light. It was concluded that the TiCl4 concentration in the post-treatment of the TiO2 mesoporous layer, the electrolyte composition, and the sensitization conditions must be adjusted depending on the light intensity (1 sun vs indoor illumination). The best-performing devices exhibited record power conversion efficiencies (PCEs) for M-DSSC: PCE of 10.9% under simulated AM1.5G, stable for 1000 h under natural aging, and PCEs of 27.3% and 30.2% under 600 and 1000 lx indoor light, respectively, stable for 1000 h under continuous 1000 lx illumination.