Study On Carbon Electrode Of Perovskite Solar Cells

Organic-inorganic hybrid metal halide perovskite has excellent photoelectric properties,adjustable components and bandgap,and also can be prepared by solution.It has attracted worldwide attention.The photoelectric conversion efficiency of perovskite solar cells?PSC?has reached to 22.7%at an astonishing speed in five years,showing its great development and application prospects.Compared with the traditional structure of PSC based on the noble metal electrode and the organic hole transmission material?HTM?,the printable mesosocopic perovskite solar cells?MPSC?,which is based on the mesoporous triple-layer of TiO₂/ZrO₂/Carbon?perovskite?,have demonstrated its great potential as a cheap and stable application of solar cells,no matter from the perspective of technology and materials.However,the efficiency climbing speed of MPSC is still lagging behind the traditional PSC.In this paper,from the view of cheap and stable carbon electrode in MPSC,we developed a low temperature carbon electrode,which is highly conductive,robust,compatible with perovskite materials and also owns suitable work function.Then we apply it to improve the efficiency of MPSC.At the same time,a double hybrid carbon electrode with high work function was developed to reveal the influence of the work function of carbon electrode on the photovoltaic parameters of MPSC.In addition,the low temperature carbon electrode is extended to other heterostructure perovskite solar cells based on carbon electrode?c-PSC?.Finally through the method of atomic layer depositon?ALD?,we deposite the metal oxide film on the interface of carbon electrode with mesoporous channels in MPSC and successfully get an encapsulation waterproof on MPSC.The results provide more theoretical support for the future development of low cost and stable MPSC.The main contents of this paper include:We developed a low temperature carbon electrode with high electrical conductivity,high mechanical strength.Also it has the suitable work function and can be compatible with perovskite materials.After replaced the traditional macromolecular organic polymer binder such as PVAc used in carbon paste,etc,we used the mixed functional additives of isopropyl titanate?TTIP?,acetic acid?HAc?and alpha terpineol?Terp?,which will be reacted with each other and generate the bond of Ti-O containing groups of ester compounds to be binder and plasticizer in the carbon paste.Then the optimal conductivity is as high as 1.13 x 10⁴ S m^-1.Then we apply the low temperature carbon electrode in MPSC to adjust the structure and get the highest conversion efficiency of 14.04%.At the same time,the series resistance?R_s?of the device decreased from 21?cm² to 13?cm²,showing the application prospect of large area MPSC.We designed a new structure of MPSC based on double hybrid carbon electrode.It is composed of a layer of carbon materials with different inorganic p-type metal oxide?m-C?,which processes high work function,and another layer of high electrical conductivity of carbon electrode?c-C?.By optimizing the content of p-type metal oxide in m-C to vary the work function of carbon electrode and also change the thickness of the ZrO₂ insulating spacer layer,we reaveled the relationship between the work function of carbon electrode and the open circuit voltage of MPSC device?Voc?.We developed the low carbon electrode with perovskite materials compatibility features and suitable work function into the application of C-PSC,through further exploring its proper annealing process,then obtained a photovoltaic efficiency of 11.74%.These results can broad the application range of low carbon electrode and also seek for more possibilities for the development of PSC basd on carbon electrode in the future.We comibined the advantage of atomic laryer deposition?ALD?,which can deposite dense and uniform metal oxide films,to modify the surface of mesosporoous carbon electrode in MPSC.By exploring the suitable process parameters,the pores in mesoporous carbon electrode can be modified by dense Al₂O₃ nanoparticles successfully,then it can realize an encapsulation waterproof for MPSC successfully.This work provide reference for the future work about water stability of MPSC.