The Application Of Modular Architecture In C-based PSCs And The Study Of Interface Optimization In Device

In recent years,the conventional energy crisis has been heavily hampering the development of human society,while the effective development of new energy sources such as solar energy is one of the effective methods to solve the energy crisis.In the few last years,metal halide perovskites have exhibited tremendous potential,and the current certified power conversion efficiency(PCE)of perovskite solar cells(PSCs)rapidly increased to 25.5%in ten years.Compared to other solar cells,PSCs holds noticeable superiority in their simple manufacturing processes,low-cost and rich resource.However,most PSCs applied organic HTLs(Spiro-Me OTAD)and noble metals as back electrodes,which severely limiting the long-term stability of the device.Now,the carbon-based HTL-free PSCs have emerged recently as a promising method for improving the stability performance of device.In order to improve the overall opto-voltage performance,the interface between perovskite and carbon electrode was modified and various carbon source electrode materials were systematically studied in this paper.Based upon above studies,a facile repair and maintenance modular structure of PSCs was proposed,related results are as follows:(1)The perovskite/carbon interface needed to be further improved in a bid for efficient photo-generated charge extraction.In here,the mixed perovskite active layers Cs_0.05(FA_0.85MA_0.15)_0.95Pb(I_0.85Br_0.15)₃were obtained using the anti-solvent one-step spinning process,in which the oxidized multi-walled carbon nanotubes(O-MWCNTs)were dispersed in an anti-solvent solution(chlorobenzene).By examining the optimized concentration for the best overall performance,we have certainty that the concentration of 0.5mg ml^-1are more favorable for the obtaining of high crystallinity perovskite films.Meanwhile,the related crystallization method enables the penetration of O-MWCNTs into both layers and the formation of a perovskite/carbon hetero-junction,thus forming a fast hole transport pathway from perovskite to carbon electrode with improved quality of perovskite/C-electrode interface.The C-based HTL-free PSCs,wherein the interface quality of perovskite/C-electrode was modified enable the PCE increased up to 8.99%,and the unencapsulated PSCs retained80%of their initial PCE under ambient conditions without intentionally controlling humidity for 500 h.The stability performance of C-PSCs significantly improved in contrast to Ag-PSCs.(2)In carbon-based HTL-free PSCs,the carbon electrode deposition and growth process,and the selection of carbon materials is vital to device performance.Herein,we proposed a low temperature thermal spraying technology in this paper for C-electrode deposition,and also compared the structure and properties of three typical carbon resource(MWCNT,CNC,Graphene).Among them,MWCNT has been proved to be excellent candidate materials for PSCs with efficient charge extraction ability.Meantime,we make a thorough analysis on the modular interconnection architecture.The mechanism for the advanced modular interconnection architecture was elucidated with the equivalent circuit model and P-N junction diode model,which indicated an efficient charge transport,and a significantly reduced energy loss of transport process was achieved with the modular interconnection,whereby a noticeable promotion of device opto-voltage performance was achieved.