作者:Ke Gui、Karyn Mutkins、Paul E. Schwenn、Karsten B. Krueger、Almantas Pivrikas、Pascal Wolfer、Natalie Stingelin Stutzmann、Paul L. Burn、Paul Meredith
DOI:10.1039/c1jm14089b
日期:——
n-Type organic semiconductors are important for a range of optoelectronic applications including organic photovoltaic devices, light-emitting diodes, and field effect transistors (FETs). In spite of this clear motivation there has been significantly less development of n-type compounds relative to p-type systems. We have developed a simple, small molecule n-type material, 2-[(7-9,9-di-n-propyl-9H-fluoren-2-yl}benzo[c][1,2,5]thiadiazol-4-yl)methylene]malononitrile (K12), that can be processed either by spin-coating from solution or evaporation in vacuum. The thermal properties of K12 enable the film morphology to be controlled at easily accessible temperatures allowing the charge mobility to be tuned over two orders of magnitude. The electron mobility in the films was found to be independent of the initial processing conditions (solution or evaporation). The electron mobility measured in a FET configuration was of the order of 10−3 cm2 V−1 s−1 for films prepared via either processing method whilst Photoinduced Charge Extraction in Linearly Increasing Voltage (PhotoCELIV) gave a mobility of order 10−4 cm2 V−1 s−1.
n 型有机半导体对于一系列光电应用非常重要,包括有机光伏器件、发光二极管和场效应晶体管(FET)。尽管动机明确,但相对于 p 型系统,n 型化合物的开发明显较少。我们已经开发出一种简单的小分子 n 型材料,即 2-[(7-9,9-二正丙基-9H-芴-2-基}苯并[c][1,2,5]噻二唑-4-基)亚甲基]丙二腈(K12),它可以通过从溶液中旋涂或在真空中蒸发的方式进行加工。利用 K12 的热特性,可以在易于控制的温度下控制薄膜的形态,从而调整电荷迁移率,使其达到两个数量级以上。研究发现,薄膜中的电子迁移率与初始加工条件(溶液或蒸发)无关。通过这两种加工方法制备的薄膜,在场效应管配置中测得的电子迁移率为 10-3 cm2 V-1 s-1,而线性增加电压下的光诱导电荷提取(PhotoCELIV)得出的迁移率为 10-4 cm2 V-1 s-1。