In Situ Growth of MoS₂ Onto Co-Based MOF Derivatives Toward High-Efficiency Quantum Dot-Sensitized Solar Cells

Quantum dot sensitized solar cells (QDSCs) represent a promising third-generation photovoltaic technology, boasting a high theoretical efficiency of 44% and cost efficiency. However, their practical efficiency is constrained by reduced photovoltage (V_oc) and fill factor (FF). One primary reason is the inefficient charge transfer and elevated recombination rates at the counter electrode (CE). In this work, a novel CE composed of a titanium mesh loaded with Co,N─C@MoS₂ is introduced for the assembly of QDSCs. The incorporation of nanosized MoS₂ enhances the density of catalytic sites, while the Co,N─C component ensures high conductivity and provides a substantial active surface area. Additionally, the titanium mesh's 3D structure serves as an effective electrical conduit, facilitating rapid electron transfer from the external circuit to the composite. These improvements in catalytic activity, charge transfer rate, and stability of the CE significantly enhance the photovoltaic performance of QDSCs. The optimized cells achieve a groundbreaking power conversion efficiency (PCE) of 16.39%, accompanied by a short-circuit current density (J_sc) of 27.26 mA cm^-2, V_oc of 0.818 V, and FF of 0.735. These results not only offer a new strategy for designing electrodes with high catalytic activity but also underscore the promising application of the Co,N─C@MoS₂ composite in enhancing QDSC technology.