Murrey Tucker L, Riley Margaret A, Gonel Goktug, Antonio Dexter D, Filardi Leah, Shevchenko Nikolay, Mascal Mark, Moulé Adam J
Department of Material Science and Engineering, University of California, Davis, Davis, California 95616, United States.
Department of Chemical Engineering, University of California, Davis, Davis, California 95616, United States.
J Phys Chem Lett. 2021 Feb 4;12(4):1284-1289. doi: 10.1021/acs.jpclett.0c03620. Epub 2021 Jan 26.
High electron affinity (EA) molecules p-type dope low ionization energy (IE) polymers, resulting in an equilibrium doping level based on the energetic driving force (IE-EA), reorganization energy, and dopant concentration. Anion exchange doping (AED) is a process whereby the dopant anion is exchanged with a stable ion from an electrolyte. We show that the AED level can be predicted using an isotherm equilibrium model. The exchange of the dopant anion (FeCl) for a bis(trifluoromethanesulfonamide) (TFSI) anion in the polymers poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly[3-(2,2-bithien-5-yl)-2,5-bis(2-hexyldecyl)-2,5-dihydropyrrolo[3,4-]pyrrole-1,4-dione-6,5-diyl] (PDPP-2T) highlights two cases in which the process is nonspontaneous and spontaneous, respectively. For P3HT, FeCl provides a high doping level but an unstable counterion, so exchange results in an air stable counterion with a marginal increase in doping. For PDPP-2T, FeCl is a weak dopant, but the exchange of FeCl for TFSI is spontaneous, so the doping level increases by >10× with AED.
高电子亲和势（EA）分子对低电离能（IE）聚合物进行p型掺杂，基于能量驱动力（IE - EA）、重组能和掺杂剂浓度产生平衡掺杂水平。阴离子交换掺杂（AED）是一种掺杂剂阴离子与电解质中的稳定离子进行交换的过程。我们表明，可以使用等温平衡模型预测AED水平。在聚合物聚（3 - 己基噻吩 - 2,5 - 二基）（P3HT）和聚[3 - （2,2 - 联噻吩 - 5 - 基） - 2,5 - 双（2 - 己基癸基） - 2,5 - 二氢吡咯并[3,4 - ]吡咯 - 1,4 - 二酮 - 6,5 - 二基]（PDPP - 2T）中，掺杂剂阴离子（FeCl）与双（三氟甲磺酰胺）（TFSI）阴离子的交换分别突出了该过程非自发和自发的两种情况。对于P3HT，FeCl提供高掺杂水平但反离子不稳定，因此交换导致形成空气稳定的反离子，掺杂略有增加。对于PDPP - 2T，FeCl是一种弱掺杂剂，但FeCl与TFSI的交换是自发的，因此通过AED掺杂水平增加>10倍。
