Morphology Associated Positive Correlation between Carrier Mobility and Carrier Density in Highly Doped Donor–Acceptor Conjugated Polymers

• DOI: 10.1002/adfm.202212825
• Publication Date: 2023-02-24T04:19:41Z
• Authors: Jiwoo Min; Jaemin Im; Seung Hyun Kim; Hyun Ho Choi; Kilwon Cho
• Keywords: Acceptor; Charge carrier; Electron Mobility

Abstract Molecular doping in conjugated polymers (CPs) has recently received intensive attention for its potential to achieve high electrical conductivity organic thermoelectric materials. In particular, it affects not only the carrier density n but also mobility µ because degree of molecular changes morphological properties. Herein, effect CP thin films on pathways and mechanisms charge transport is investigated, which govern ‐ relationship. Two representative donor–acceptor type CPs with similar different assembly an undoped state, that poly[2,5‐(2‐octyldodecyl)‐3,6‐diketopyrrolopyrrole‐ alt ‐5,5‐(2,5‐di(thien‐2‐yl)thieno[3,2‐b]thiophene)] (DPPDTT) indacenodithiophene‐ co ‐benzothiadiazole (IDTBT), are prepared. Heavy iron chloride (FeCl 3 ) induced DPPDTT highly crystalline edge‐on orientation increase up 19.6 cm 2 V −1 s , whereas IDTBT irregular intermolecular stacking showed little change . It revealed this relationship attributed initial ordering films. The mechanism becomes significantly different: both coherent incoherent transports observed doped DPPDTT, found IDTBT. This study suggests guidelines enhancing under terms structural disorder.