Study On Interface Optimization For Si/PEDOT:PSS Heterojunction Solar Cells

Solar energy is an important choose for humans to solve the energy and environmental problems,and has received more and more attention all over the world.The Si/PEDOT:PSS heterojunction solar cell(HSC)exhibits the advantages of economic processing and high theoretical photon-to-electron conversion efficiency(PCE).Although such has been extensively studied,but its efficiency still shows great potential for further improvement.The interface of Si/PEDOT:PSS HSC has very important effect on the performance of solar cell.High quality interface will enhance the light absorption and facilitate the carrier separation,which can help improving the performance of solar cell.Thus,focusing on the interface optimization and efficiency improvement of Si/PEDOT:PSS HSC,silicon surface hydroxylation and the introduction of MWCNTs?PDA,DA@G film were performed to optimize the interface and improve the performance of solar cell.The main results are as follows:(1)After the silicon surface hydroxylation was realized through the Na OH solution with low concentration,the fill factor(FF)and short-circuit current(J_sc)were enhanced.When silicon surface hydroxylation,the wettability of silicon surface was promoted along with the interface contact,which would facilitate the carrier separation.Meanwhile,the silicon surface was also etched,and the light trap ability was strengthed.When the silicon was immersed in Na OH solution for 15 min,the prepared solar cell showed the highest PCE with 12.05%.(2)When the MWCNTs?PDA film was introduced,the fill factor(FF)and short-circuit current(J_sc)were enhanced,and open-circuit voltage(V_oc)also has been improved.After the MWCNTs?PDA film was introduced,the antireflection was greatly improved,and the light utilization and absorption of solar cell was promoted.Besides,the film could suppresses the charge recombination and improve the junction quality.When the concentration of MWCNTs in MWCNTs?PDA film was 1 mg/ml,the prepared solar cell exhibited the most outstanding PCE with 12.49%.(3)When the DA@G film was introduced,the fill factor(FF)and short-circuit current(J_sc)were enhanced.After the DA@G film was introduced,the antireflection of solar cell within the wavelength range 300?450 nm and 650?1100 nm was greatly improved,and the light utilization and absorption of solar cell was promoted.Besides,the carrier separation was facilitated owing to the optimized interface.When the concentration of graphene in DA@G film was 1.5 mg/ml,the prepared solar cell exhibited the most outstanding PCE with 13.15%.