The solution method interface materials commonly used in organic solar cells are metal oxide nanomaterials and polymer/small molecular organic interface layer materials. Both types of interface materials have advantages and disadvantages in practical applications, such as metal oxide nanomaterials. There are many surface defects and easy to aggregate; the organic interface material has strict thickness control and the optimal thickness is within 10 nm, which is not suitable for printing. For these problems, Luo Qunhe, associate researcher of Suzhou Nanotechnology and Nano-Bionics Institute, Chinese Academy of Sciences Researcher Ma Changyu developed a nanocomposite interface material based on metal oxide nanoparticles and polymers. The structure, physicochemical properties, optoelectronic properties of hole transport and electron transport composites were systematically studied. The results show that the composites have Excellent film-forming properties and photoelectric properties. The metal oxide nanomaterials are compounded with the polymer to alleviate the agglomeration of the metal oxide nanomaterials; on the other hand, the polymer material is avoided in terms of film thickness due to conductivity. Limitations. This material is used in organic and perovskite films. In the pool, the dependence between device performance and interface layer thickness can be reduced, which will help to reduce the difficulty of the printing process, improve process repeatability and battery yield. Related work results published in ACS Appl. Mater. Interfaces 2015 , 7, 7170-7179; Sol. Energy Mater. Sol. Cells 2015, 141, 248-259; ACS Appl. Mater. Interfaces 2016, 8, 18410-18417; Org. Electron. 2016, 38, 150-157; Org Electron. 2017, 45, 190-197.
Due to the good film-forming properties, printability and electrical conductivity of the composite interface materials, the research team further used such materials in fully coated organic solar cells, and found that printed nano-silver wire networks showed more on this type of interface layer. Uniform distribution (Fig. 2). Based on this characteristic, the research team combined the coated interface layer and the sprayed nano-silver wire electrode to prepare a high-performance translucent fully coated organic solar cell, which verified the preparation of the whole solution method. Feasibility of highly efficient translucent organic thin film photovoltaic cells. The results are published in ACS. Appl. Mater. Interfaces, 2018, 10, 943-954.
Recently, for printing film applications, the interface material ink requires long-term stability and low thickness dependence. The research team proposed a new idea of surface chemical graft modification of metal oxide nanomaterials, and the chemically functional surface interface The branch unit is directly modified on the surface of the nano metal oxide, thereby improving the chemical stability and functional modification properties of the organic-inorganic composite nanomaterial. The zinc oxide is selected as the research object, and the silane coupling agent is used to modify it. The zinc oxide nanoparticles synthesized by the solution method contain a large amount of hydroxyl groups, which tend to cause agglomeration of the nanomaterials, and adsorb a large amount of oxygen, thereby causing unsatisfactory ink stability and device interface charge accumulation. The research team passed surface hydroxyl groups and siloxanes. Ligand exchange of the base to obtain a class of zinc oxide nanomaterials based on silane coupling agent modification (Fig. 3). This material is used in organic inverted solar cells to suppress the common 'light bath' phenomenon. After being stored in the atmosphere for at least 1 year, the nanoparticles do not show obvious aggregation; One year of ink preparation interface materials can also achieve excellent device performance, providing new ideas for the development of high stability printable nano-ink materials. The results of this study were recently published in ACS Nano, 2018, 12, 5518- 5529.
The above research work was supported by the National Natural Science Foundation of China (51773224, 61306073), the Chinese Academy of Sciences Pilot Project (No. XDA09020201), and the Jiangsu Provincial Science and Technology Department Industry Prospect and Common Technology Project (BE2015071). At the same time, it was awarded the cooperation unit of the University of Science and Technology of China. Support from the team of Yang Nanliang, professor at Suzhou Nano School and School of Physics and Microelectronics, Central South University.