Study On The Influence Of Anode Interface Modification Layer On Organic Polymer Solar Cells

With the rapid development of the global economy,the growing consumption of traditional energy leads to the world-scale energy crisis.At the same time,the excessive use of fossil fuels makes environmental pollution threaten people's lives.Therefore,solar energy that is abundant,clean and renewable has become the ideal alternative energy.The organic solar cells developed in the past two decades have become a hotspot in the research field because of the potential of large-scale and low-cost preparation,flexible battery and simple preparation process.At present,the energy conversion efficiency of organic solar cells has reached more than 10%,but this number is far from the requirements of large-scale production.The interface modification layer plays an important role in improving the photovoltaic performance and stability of the organic solar cells.The interface modifying layer may be a conductive polymer,metal oxide or other nanostructured materials.In this paper,new types of anode buffer layers are mainly introduced to overcome the shortcomings of the anode interface modification layer commonly used in organic solar cells.1.We design a bi-layer structure consisting of PTFE and MoO₃ as anode buffer layer and introduce the PTFE/MoO₃ bi-layer in the device structure of ITO/PTFE/MoO₃/PCDTBT:PC71BM/Alq3/Al to substitute for the PEDOT:PSS and the bare MoO₃ commonly used at present.PTFE/MoO₃ bi-layer structure will form a interface dipole on the surface of ITO,improving the surface work function of ITO and modifying the interface energy difference between ITO and active layer,which is beneficial to hole extraction.At the same time,compared with PEDOT:PSS,PTFE/MoO₃ bi-layer has stable physical and chemical properties and moisture resistance,as well as not corroding ITO.Compared with bare MoO₃ layer,the PTFE/MoO₃ bi-layer structure enhances the ability of blocking electrons and reduces the recombination probability of electrons and holes.As a result,the performance of the device has been greatly improved.2.Graphene-based materials have a wide range of applications in organic solar cells because of their good electrical properties,optical properties and mechanical properties.In this experiment,we synthesize the graphene oxide?GO?material by the improved Hummers method.Then GO is prepared to an aqueous solution by ultrasonic and deposited into GO film layer by spin coating method.A device with the structure of ITO/GO/PCDTBT:PC71BM/LiF/Al is fabricated by using GO film as anode buffer layer.The device with GO film as anode buffer layer which can be solution-processed has a simple preparation process and is more conducive to the realization of large-scale production.The GO solution is neutral and will not corrode the anode electrode like PEDOT:PSS.In addition,the introduction of GO reduces the energy barrier height between ITO and PCDTBT,which is conducive to the holes extraction.As a result,the device achieves a similar efficiency to device with PEDOT: PSS as buffer layer.Based on the above two experiments,we have studied the influences of anode interface modification layer on the performance of organic polymer solar cells.Aiming at the shortcomings of the commonly used anode interface modification layer,we have proposed some solutions and successfully fabricated low-cost and high-performance devices,which provides a reference for the commercialization of organic solar cells.