Nano Institute of Utah and Department of Materials Science and Engineering, University of Utah , 36 South Wasatch Drive, Salt Lake City, Utah 84112, United States.
Vaporsens, Inc. , 36 South Wasatch Drive, Salt Lake City, Utah 84112, United States.
ACS Appl Mater Interfaces. 2016 May 18;8(19):12360-8. doi: 10.1021/acsami.6b03151. Epub 2016 May 9.
Intrinsically low electrical conductivity of organic semiconductors hinders their further development into practical electronic devices. Herein, we report on an efficient chemical self-doping to increase the conductivity through one-dimensional stacking arrangement of electron donor-acceptor (D-A) molecules. The D-A molecule employed was a 1-methylpiperidine-substituted perylene tetracarboxylic diimide (MP-PTCDI), of which the methylpiperidine moiety is a strong electron donor, and can form a charge transfer complex with PTCDI (acting as the acceptor), generating anionic radical of PTCDI as evidenced in molecular solutions. Upon self-assembling into nanoribbons through columnar π-π stacking, the intermolecular charge transfer interaction between methylpiperidine and PTCDI would be enhanced, and the electrons generated are delocalized along the π-π stacking of PTCDIs, leading to enhancement in conductivity. The conductive fiber materials thus produced can potentially be used as chemiresistive sensor for vapor detection of electron deficient chemicals such as hydrogen peroxide, taking advantage of the large surface area of nanofibers. As a major component of improvised explosives, hydrogen peroxide remains a critical signature chemical for public safety screening and monitoring.
有机半导体的本征电导率低阻碍了其进一步发展为实际的电子器件。在此，我们报告了一种有效的化学自掺杂方法，通过一维堆叠排列的电子给体-受体（D-A）分子来提高电导率。所采用的 D-A 分子是 1-甲基哌啶取代的苝四羧酸二酰亚胺（MP-PTCDI），其中甲基哌啶部分是一个强电子给体，可以与 PTCDI（作为受体）形成电荷转移复合物，在分子溶液中生成 PTCDI 的阴离子自由基。通过柱状 π-π 堆积自组装成纳米带后，甲基哌啶和 PTCDI 之间的分子间电荷转移相互作用会增强，生成的电子沿 PTCDI 的 π-π 堆积发生离域，从而提高电导率。由此产生的导电纤维材料可作为对电子缺乏化学品（如过氧化氢）蒸气检测的化学电阻传感器，利用纳米纤维的大表面积。过氧化氢作为简易爆炸物的主要成分，仍然是公共安全筛查和监测的关键特征化学品。
