Exploring Charge Transport in High‐Temperature Polymorphism of ITIC Derivatives in Simple Processed Unipolar Bottom Contact Organic Field‐Effect Transistor. (10th December 2021)

• Record Type: Journal Article
• Authors: Avalos Quiroz, Yatzil Alejandra; Koganezawa, Tomoyuki; Perkhun, Pavlo; Barulina, Elena; Ruiz, Carmen M.; Ackermann, Jörg; Yoshimoto, Noriyuki; Videlot‐Ackermann, Christine
• Is Part Of: Advanced Electronic Materials. Volume 8:Number 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-10
• Subjects: dielectric passivation -- electron mobility -- J‐aggregate -- nonfullerene acceptors -- polymorphism -- thermal stability -- thin‐film transistors; Materials -- Electric properties -- Periodicals; Materials science -- Periodicals; Magnetic materials -- Periodicals; Electronic apparatus and appliances -- Periodicals; 537
• DOI: 10.1002/aelm.202100743
• Languages: English
• ISSNs: 2199-160X

Abstract

Abstract: Power conversion efficiency of organic solar cells increases continuously due the emergence of novel nonfullerene acceptors (NFAs). As solar cell efficiency is governed by photogeneration followed by charge carrier transport toward the electrode, understanding of univocal electron transport properties of NFAs is of great importance. Acceptors from the indacenodithienothiophene‐based family such as ITIC, ITIC‐Th, and ITIC‐4F have been intensively studied in solar cells. Importantly, ITIC‐ and ITIC‐4F‐based films evolve with increasing annealing temperature from 100 ° C up to 250 ° C into several polymorphs that may impact the electronic transport strongly. Here, for the first time, the effects of temperature‐dependent polymorphism on the charge transport properties of ITIC, ITIC‐Th, and ITIC‐4F are studied. A unipolar, high performance, and high‐temperature stable thin‐film transistor structure is developed first using divinyltetramethyldisiloxane‐bis(benzocyclobutene) as dielectric passivation material to explore the intrinsic charge transport up to 240 ° C. It is shown that electron mobility in the three ITIC‐based films is strongly influenced by the molecule specific polymorphism at optimal temperatures. This leads to a strong increase in electron mobility compared to the as‐cast films, which is correlated to changes in molecule aggregation, domain crystallinity, and orientation as well as intermolecular electronic coupling. Abstract : By the development of a new unipolar high‐temperature stable bottom gate bottom contact organic thin‐film transistor structure, the electron transport in high‐temperature polymorphisms of ITIC, ITIC‐Th, and ITIC‐4F is studied. An annealing temperature‐dependent electron mobility map is obtained for each molecule highlighting that the intrinsic electron transport depends mainly on degree of molecule ordering and J‐aggregates together with intermolecular electronic coupling.