Design And Preparation Of Printable Interface Layer Materials In Organic Solar Cells

As a new generation of photovoltaic technology,organic solar cells?OSCs?have the advantages of light weight,simple manufacturing process,low materials cost,and easy preparation of large-area flexible devices through printing process,and become a new type of photovoltaic technology with important application prospects.After more than a decade of development,OSC's energy conversion efficiency?PCE?has exceeded 16%,showing great potential for application.At present,the development of large-area devices though printing technology has become a research hotspot in the filed of organic photovoltaics.The interface layer serves as a connection bridge between the electrode and the active layer.The interface layer can effectively adjust the work fuction of the electrode,and form a good ohmic contact between the electrode and active layer,which is crucial for the collection and extraction of charge.At present,interface layer materials mainly rely on the preparation method of spin coating,which limits their application in large-area devices.Therefore,research and development of printable interface layer materials are of great significance for accelerating the practical process of organic solar cells.The interface layer materials at this stage hinder their industrial application due to poor carrier transport performance.In this paper,the research work is aimed at the demand of large-area devices,and the carrier-transfer performance of the interface layer is improved by the"doping"method,thereby developing a new type of printable interface layer material,thereby improving the photovoltaic efficiency of large-area devices.This paper mainly includes two parts of work,the first part is about the design and application of the printable anode interface layer,and the second part is the design and application of the printable cathode interface layer.The details are as follows:?1?A printable anode interface layer material based on an inorganic material in an organic solar cell.The MoOx interfacial layer processed by the solution method can greatly improve the electrical conductivity of molybdenum oxide by the method of reduction doping.The Mo?VI?moiety can be partially reduced to Mo?V?by partially reducing the precursor aqueous solution of ammonium heptamolybdate using a small amount of ethylene glycol?EG?to obtain an n-doped MoOx anode interface layer.Compared with the unmodified molybdenum oxide interfacial layer,its conductivity is increased by two orders of magnitude compared to the raw material MoO₃,and the thickness is extended from 20 nm to 100 nm.Used to prepare l cm²large-area devices and achieve photovoltaic efficiency of more than 10%.?2?A printable anode interface layer material based on an organic material in an organic solar cell.Three p-type self-doping conjugated polyelectrolytes were designed and synthesized based on cyclopentadithiophene and phenyl units.By increasing the number of benzene units in the polymer backbone,the work function and optical transparency of the material can be effectively improved.The l cm² device with PCP-3B as the anode interface layer and all functional layers processed by blade coating achieved 9.67%energy conversion efficiency.?3?A printable cathode interface layer material based on an organic material in an organic solar cell.Naphthalimide-based printable organic small molecule cathode interface layer material NDI-N.The carrier transport properties of the interface layer material are greatly improved by doping,and NDI-N has both high crystallinity,good film formation and good electron transport performance.The National Institute of Metrology?NIM?has certified the l cm² large-area OSC device prepared by the blade-coating process,and the final certification efficiency is 12.20%.