Synthesis Of Composite Oxides By Solution Process And Its Application In Organic Solar Cells

Organic solar cells have a lot of advantages,such as light weight,simple fabrication process,low cost,and can be fabricated into flexible devices,which have attracted many researchers'attention.The power conversion efficiency of organic solar cells can be improved by using solvent additives,optimizing device structure,developing efficient donor and accepting materials,modifying interface energy levels,and so on.As an important part of organic solar cells,the interface transport layer is conducive to the effective transport of carriers between the organic active layer and the electrode,thus reducing the loss of optical absorption.The interface layer material mainly includes an organic interface modifying material,a metal oxide,and so on.Metal oxides such as NiO,V₂O₅,MoO₃,and WO₃ are widely used as anode interface materials,but these metal oxides are mainly prepared by vacuum deposition techniques,which is contrary to the low cost advantages of organic solar cells.The preparation of the composite metal oxide film by the solution process is simple in operation and low in cost,and the composite metal oxide can reduce the band gap and provide the photoelectric performance of the solar cell.Based on the above arguments,in this paper,the preparation of composite metal oxide?WO₃-MoO₃,MoO₃-V₂O₅,V₂O₅-CuO?by solution method is studied.The effects of composite metal oxide as anode interface materials on the performance of organic solar cells were investigated.The main content of the paper is divided into the following three parts:1.The composite metal oxide?WO₃-MoO₃?was synthesized by ammonium metatungstate(?NH₄?₆H₂W₁₂O₄₀)and ammonium molybdate?NH₄?₆Mo₇O₂₄)as the anode interface material for polymer solar cells.The mass ratio of the reactant raw materials,the precursor concentration,the spin coating speed and time,and the manner of treating the anode buffer material were investigated.When the mass ratio of the reactant raw material was 7:3,the precursor concentration was 1 mmol/l,and the spin coating speed was 3000rpm and time was 30s,the power conversion efficiency of polymer solar cell with WO₃-MoO₃ as anode interface layer was reached to 3.76%.2.The composite metal oxide?MoO₃-V₂O₅?was synthesized by molybdenum?VI?dioxy acetylacetonate(C₁₀H₁₄MoO₆)and vanadium?III?acetylacetonate(C₁₅H₂₁O₆V)and used as the anode interface material for polymer solar cells.When the mass ratio of the reactant raw material was 9:1,the precursor concentration was 5 mg/ml,and the spin coating speed and time was 4000 rpm and 40 s,the power conversion efficiency of polymer solar cell with MoO₃-V₂O₅ as anode interface layer was reached to 4.05%.3.The composite metal oxide?V₂O₅-CuO?was synthesized by vanadium?III?acetylacetonate(C₁₅H₂₁O₆V)and Cupric?II?acetylacetonate(C₁₀H₁₄CuO₄).The composite metal oxide?V₂O₅-CuO?was also used as an anode interface material in polymer solar cells.When the mass ratio of the reactant raw materials was 7:3,the precursor concentration was 15 mg/ml,and the spin coating speed was 3500 rpm,the power conversion efficiency of polymer solar cell with V₂O₅-CuO as anode interface layer was reached to 4.21%.The composite metal oxide V₂O₅-CuO has a certain application prospect as hole transporting layer in a polymer solar cell.The results show that the composite metal oxides WO₃-MoO₃,MoO₃-V₂O₅,V₂O₅-CuO as the hole transporting layer have higher hole mobility,higher optical transmittance and more matching energy levels.It is beneficial to transport the current between the organic active layer and the electrode effectively and reduce the loss of light absorption.