Full-Spectral Response Perovskite Solar Cells Through Integration of MXene Modified Near-Infrared Organic Heterojunction and Waveguide-Structure Quantum-Cutting Down-Converter

To date, lead-based perovskite solar cells (PSCs) are optimized to the extreme and achieved an efficiency of as much as 26.1%. Expanding the spectral response is one of the most effective methods for achieving further efficiency breakthroughs. In this study, integrated PSCs are constructed by combining near-infrared (NIR) organic bulk heterojunctions (BHJs) with perovskite layers to broaden the NIR spectral response range. Ultraviolet (UV)-plasma-treated MXene Nb2CTx - quantum dots (QDs) are introduced to promote exciton dissociation inside the BHJ and to solve the problems of severe nonradiative exciton recombination and open-circuit voltage (Voc) loss in IPSCs. In addition, CsPbCl3:Yb(7%),Li(2%) QDs with quantum-cutting emission and photoluminescence quantum yield of up to 170% act as down-converters to enhance the utilization of UV light. MgF2 is deposited on the quantum-cutting layer to construct a waveguide-structured anti-reflection layer and further increase UV photon utilization. The champion device achieves superior photoelectric performance with a photoelectric conversion efficiency of 24.3%, Voc of 1.17 V, a short circuit current of 26.65 mA cm-2, and a fill factor of 77.95%. Champion devices exhibit excellent UV and long-term stability. This study provides an instructive strategy for fabricating high-performance full-spectral-response PSCs. A novel full-spectral response perovskite solar cell is reported. The spectral response range of the device is extended to 1050 nm by ultraviolet-plasma-treated Nb2CTx quantum dots modified bulk organic heterojunction. The waveguide-structure quantum-cutting down-converter system greatly improves the ultraviolet light utilization rate and ultraviolet stability of the device. The champion device achieves superior photoelectric performance with a photoelectric conversion efficiency of 24.3%. image