Development of simple hole-transporting materials for perovskite solar cells

作者：Namespetra Andrew M; Hend**ee Arthur D; Welch Gregory C^*; Hill Ian G^*

来源：Canadian Journal of Chemistry, 2016, 94(4): 352-359.

DOI：10.1139/cjc-2015-0427

• solar energy
• perovskite solar cells
• hole-transport materials
• triphenyl amine
• polymer additives

Three low-cost propeller-shaped small molecules based on a triphenylamine core and the high-performance donor molecule 7,7'-[4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b: 4,5-b']dithiophene-2,6-diyl]bis[6-fluoro-4-(5'-hexyl-[2,2'-bithiophen]-5-yl)benzo[c] [1,2,5]thiadiazole] (DTS(FBTTh2)(2)) were investigated as hole-transporting materials in perovskite solar cells. Each hole-transporting material was designed with highly modular side arms, allowing for different bandgaps and thin-film properties while maintaining a consistent binding energy of the highest occupied molecular orbitals to facilitate hole extraction from the perovskite active layer. Perovskite solar cell devices were fabricated with each of the three triphenylamine-based hole-transporting materials and DTS(FBTTh2) 2 and were compared to devices with 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) hole-transporting layers. Each of our triphenylamine hole-transporting materials and DTS(FBTTh2) 2 displayed surface morphologies that were considerably rougher than that of spiro-OMeTAD; a factor that may contribute to lower device performance. It was found that using inert, insulating polymers as additives with DTS(FBTTh2)(2) reduced the surface roughness, resulting in devices with higher photocurrents.

• 出版日期2016-4