Enhancement of DSSCs using Dy³⁺-doped BaTiO₃@CaF₂ inorganic hybrid photoabsorbers

Dye-sensitized solar cells (DSSCs) can achieve significantly enhanced efficiency using novel photoabsorbing materials. The present research investigates the effect of Dysprosium (Dy³⁺) doping on inorganic photoabsorbers, specifically the barium titanate/calcium fluoride composite (BaTiO₃@CaF₂), which enhances DSSC performance when paired with a CoS counter electrode. A microwave-assisted hydrothermal method was employed to synthesize Dy³⁺-doped CaF₂ (CF:Dy) and BaTiO₃@CaF₂ (BTCF:Dy) photoabsorbers, whose structural, morphological, and optoelectronic properties were systematically investigated. In this sense, electrochemical impedance spectroscopy (EIS) revealed an improved charge accumulation capacity and prolonged charge carrier lifetime in the system composed of 90 wt% P25 + 10 wt% BaTiO₃@CaF₂:Dy (P25/BTCF:Dy). These improvements resulted in a superior photocurrent and power conversion efficiency of 3.04% outperforming 1.35% of the CF:Dy. Moreover, this significant increase in charge carrier lifetime may also be responsible for the observed improvement compared to standard TiO₂ P25 (2.87%), with an actual increase of 5.92% after the addition of 10 wt% of the photoabsorber. This enhancement highlights the potential of inorganic hybrid composites as promising candidates for advancing next-generation solar technologies, thereby driving the development of more efficient and sustainable energy conversion systems.