Construction Of Highly Efficient And Stable Non-fullerene Polymer Solar Cells Based On Anode Interface Engineering

Recently,the performance of polymer solar cells has made great progress,thanks to the continuous emergence of new organic semiconductor materials and the continuous optimization of device structures.In the construction of efficient and stable polymer solar cells,the design of the interface layer is an important aspect.The conventional anode interface material PEDOT:PSS molecule has the problems of significant acidity and easy water absorption,which will lead to poor device stability.Therefore,transition metal oxides such as MoO₃ and WO_x have become a potential alternative.The main contents of this paper are as follows:1)Preparation of MoO₃ anode interface layer based on ultraviolet photolysis and its application in polymer solar cells:After spin coating metal chloride?Mo Cl₅?precursor solution film formation,proceed ultraviolet radiation treatment can obtain MoO₃ anode interface layer,this method is called"ultraviolet photolysis method".Obviously,the ultraviolet photolysis method has a simple preparation process and low cost,does not require high temperature treatment,and is suitable for large-scale production and flexible substrates.Ultraviolet photoelectron spectroscopy?UPS?was used to measure the surface work function,and X-ray photoelectron spectroscopy?XPS?,atomic force microscopy?AFM?and contact angle tester were used to test the composition,surface morphology and moisture of the MoO₃anode interface layer.Based on the MoO₃ anode interface layer,and using PBDB-T and ITIC as the active layer,the solar cell device was constructed.The efficiency of the device based on the optimized MoO₃ anode interface layer is as high as 9.27%,while the efficiency of the device based on pure ITO and ITO/PEDOT:PSS as the control is 3.69%and 9.15%,respectively.Moreover,the device exhibited better stability.2)Preparation of WO_x anode interface layer based on ultraviolet photolysis and its application in polymer solar cells:Based on the above-mentioned ultraviolet photolysis method,a WCl₆ precursor solution was used to prepare the WO_x anode interface layer.UPS,XPS,AFM and contact angle tester were used to test and analyze the surface characteristics of ITO based on WO_x anode interface layer.The device efficiency based on the optimized WO_x anode interface layer is 8.56%,which is significantly higher than the device efficiency based on pure ITO.Moreover,the device also has excellent stability.3)Application of nano-particle type MoO_x anode interface layer in polymer solar cells:low-cost MoO_x nano-particle solution is used to prepare anode interface layer.The surface morphology of the film,the external quantum efficiency of the device,and the current and voltage tests in the dark state show that MoO_x nanoparticles as the anode interface layer can play a good modification in the device.Finally,the efficiency of the anode interface layer inverted device based on MoO_x nanoparticles is 8.97%.In summary,the MoO₃,WO_x anode interface layer prepared based on the ultraviolet photolysis method and the nanoparticle-type MoO_x anode interface layer can effectively improve the performance of the device,which shows that the transition metal oxide anode interface layer is of great value for the construction of efficient and stable polymer solar cells.