Research Progress of Electron Transport Layer Materials for Organic Solar Cells

With the continuous progress of human society and the rapid development of science and technology, as a kind of renewable energy, solar energy has attracted much attention in the era of resource shortage. Due to its advantages such as low cost, abundant reserves and simple use, solar energy has attracted many researchers to study and explore. As a new generation of solid-state thin-film cells, organic solar cells have presented a revolutionary challenge to the expensive commercialized inorganic silicon solar cells by their application prospects of solution processing, roll-to-roll printing and printing to fabricate flexible devices. However, at the present stage, organic solar cells still have the defects of relatively weak stability and low power conversion efficiency. Although the reported power conversion efficiency of organic solar cells has reached 16.70%, it is still a long way for realizing their commercial application. Electron transport layer plays an important role in the device and exerts asignificant influence on the power conversion efficiency and stability of the organic solar cells. At present, the electron transport materials used in organic solar cells are mainly metal fluorides, n-type metal oxides, organic small molecules, polymer electrolytes and fullerenes. Among these electron transport materials, organic electron transport layer materials have attracted much attentive because of their adjustable structure, soluble processing and large area printing, etc. In this paper, organic electron transport materials are summarized, including polyfluorenes, poly-thiophenes, phthalimides and fullerenes. The purpose is to illustrate the existing research progress, compare and analyze the advantages and disadvantages of various electronic transport materials, and prospect the development trend and research prospect of electronic transport materials. © 2020, Materials Review Magazine. All right reserved.