Abstract
Quantum dot-sensitized solar cells (QDSSCs) present a compelling alternative to traditional photovoltaic technologies due to the unique optoelectronic properties of semiconductor nanocrystals, including tunable bandgaps and multiple exciton generation. However, the long-term operational stability and power conversion efficiency (PCE) of QDSSCs remain significant hurdles for commercial integration, particularly concerning the degradation of quantum dots (QDs) under environmental and photo-induced stressors. This study, conducted in early 2026, investigates a novel hybrid architecture utilizing perovskite-based encapsulation to protect cadmium selenide (CdSe) and lead sulfide (PbS) quantum dots. By integrating a thin-film perovskite passivation layer, we aim to mitigate recombination losses and prevent the oxidation of the QD sensitizers. Methodologically, chemical bath deposition was employed to sensitize TiO2 photoanodes, followed by a controlled vacuum-assisted perovskite encapsulation process. Our results demonstrate that the encapsulated QDSSCs retain over 92% of their initial efficiency after 1000 hours of continuous illumination, a marked improvement over the 65% retention observed in non-encapsulated control devices. Furthermore, the short-circuit current density (Jsc) increased by 14% due to improved charge extraction dynamics at the QD/perovskite interface. These findings suggest that the synergy between metal halide perovskites and quantum dots provides a robust pathway for achieving high-performance, durable third-generation solar cells. The study concludes that hybrid encapsulation strategies are essential for the future of flexible and cost-effective solar energy applications.