The Effect Of Carbon-Based Perovskite Solar Cell

With the development of society,the demand for traditional fossil energy has increased dramatically,while fossil energy is non-renewable energy.So it is nervous for human beings to focus on various renewable alternative energy sources.Solar energy has the advantages of clean and renewable,which can be said to be inexhaustible,and is the richest energy in the world.Therefore,the study of high efficiency and low cost solar cells has great practical significance for solving the world energy crisis.The perovskite solar cells have become one of the most important research topics due to direct band gap,larger absorption coefficient and higher carrier mobility.However,the perovskite solar cells(PSCs)use a noble metal as a counter electrode,which is not only expensive for precious metal materials,but also requires high energy deposition technology.At the same time,the expensive hole transport layers makes the increased PSC cost substantially.Therefore,there is an important practical value in the search for inexpensive,stable materials to replace noble metals as counter electrodes.Carbon materials have not only the characteristics of structural diversity,chemical stability and rich surface chemical properties,but also the advantages of low price and easy preparation.At the same time,the work function of carbon is similar to that of Au.It is a better choice to replace the noble metal electrode by carbon materials.In this paper,we prepare carbon-based perovskite solar cells without hole transport layer by replacing noble metal electrodes.The main contents of this paper are as follows:1.Here we successfully achieve highly-conductive carbon electrode by using polystyrene(PS)as binder,graphite carbon black as carbon material and ethyl acetate as solvent to prepare a new carbon paste.PS is a polymer synthesized by free radical addition of styrene monomer.It is a colorless transparent thermoplastic with excellent adhesion,optical properties and electrical properties.The experimental results show that PS as a binder improves the close contact between graphite and carbon black,and has a significant impact on the performance of perovskite solar cells.By optimizing the quantity of PS,the power conversion efficiency(PCE)reached 8.20%.During 15 days storage,the photoelectric conversion efficiency remained at 82% of the initial value.2.Perovskite solar cells with carbon electrodes are prepared by changing the preparation process of carbon electrodes.Carbon electrodes are prepared by vibration method,and the vibration frequency is optimized.The efficiency of the perovskite solar cell is increased to 12.48%.The perovskite solar cells prepared by vibration treatment improves the contact between graphite and carbon black as well as the contact between carbon electrode and perovskite layer,thus improving the efficiency of the solar cell.And during 15 days storage,it still has good stability,and the efficiency remains at the original 90%.