Design And Synthesis Of New Metal Oxides And Their Application In Organic Solar Cells

Organic solar cells have garnered considerable attention due to their flexibility,lightweight,and potential for large-area printing.Although the photoelectric conversion efficiency of OSCs has surpassed 20%thanks to advancements in organic photovoltaic materials and device preparation technology,there remains ample room for improvement in efficiency and stability.Of particular importance is the charge transport layer,which plays a critical role in OSC performance and stability.However,research on hole transport materials lags that of electronic transport materials.Commonly used hole transport layers,such as poly[3,4-ethylenedioxythiophene]:poly[styrenesulfonate]（PEDOT:PSS）and Mo O₃,present challenges including device instability and limitations in large-scale production.Consequently,the development of efficient,stable,and easily processed hole transport materials is crucial for OSC commercialization.Additionally,the lack of flexible composite electrodes with high transmittance,high operating temperature,solvent tolerance,and excellent mechanical properties hinders the development of flexible organic solar cells.This article aims to address these challenges by focusing on the practical application of flexible organic solar cells and developing high-performance hole transport layer materials and flexible composite electrodes to facilitate their commercialization process.Specifically,the research has achieved the following results:（1）Development of a novel cobalt-lanthanum Co-La composite hole transport material,processed into an efficient and stable hole transport layer via low-temperature annealing without additional high-temperature or ultraviolet-ozone treatment steps.This material achieved a device efficiency of 18.82%in PM6:L8-BO devices,setting a record for the highest efficiency of two components at that time,while exhibiting excellent stability.（2）Directional regulation of Ni O_x nanoparticles’properties through doping with different radii of rare earth ions.The closer the radius of the rare earth ion to that of the nickel ion,the higher the doping efficiency.Sc³⁺achieved a doping concentration of up to 5%,significantly improving conductivity and optimizing work function.Surface defect reduction with catechol further increased device efficiency to 19.18%,setting a record for solution-processed nanoparticle-based hole transport layers.（3）Low-temperature preparation of Mo O_x thin films achieved through doping with reducing metal ions,significantly improving conductivity and optimizing energy level structure.This reduced the processing temperature of the sol-gel Mo O_x film from 200°C to 150°C,realizing low-temperature preparation.Application of this optimized Mo O_x thin film to organic solar cells resulted in an efficiency of 18.43%,with enhanced optical and thermal stability.（4）Successful preparation of an organic-inorganic hybrid cross-linked flexible transparent polyimide using inorganic titanium oxide clusters and a ligand exchange strategy.The cross-linked material exhibited improved solvent resistance,high temperature resistance,and mechanical properties,while remaining recyclable.Semi-embedded silver nanowires into the substrate yielded Ag NWs@HCPI electrodes with good transparency,solvent resistance,and high mechanical resistance.Flexible organic solar cells based on this composite electrode achieved a PCE of 14.78%,maintaining over 97%of initial efficiency after 5000 bending cycles with a small bending radius of 1 mm.Additionally,HCPI remained recyclable even after fabrication into flexible organic solar cells.