Modulating Charge Transport from Thermally Activated to "Band‐Like" Through Interfacial Bottom‐Up Binding Capability of Bilayer Polymer Dielectrics. (25th December 2022)

• Record Type: Journal Article
• Authors: Zheng, Yingshuang; Lin, Hongzhen; Jiang, Ting; Zhu, Dongyang; Qi, Shengli; Li, Wei; Li, Liqiang; Ji, Deyang; Hu, Wenping
• Is Part Of: Advanced functional materials. Volume 33:Number 10(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-25
• Subjects: band‐like transport -- interface engineering -- organic semiconductors -- polymer dielectrics -- thin‐film transistors; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202211742
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The disordered chain arrangement of polymer dielectrics has complex both internal and external effects on system performance, which generally stimulates the weak acquisition and grain boundaries of vapor‐deposited organic small molecule films (VDOSMFs) with thermally activated charge transport. As a result, achieving "band‐like" transmission of VDOSMs on polymer dielectrics is attempting to prove to be a major challenge. Three types of bi‐polymer dielectrics are developed to modulate charge transport from thermally activated mode to "band‐like" transport at the interfacial level. The bottom consisting of a polyimide layer is critical to interfacial modulation, which shows the selectively binding capability with up‐dielectric layers to realize the modulation of charge transport, as corroborated by interface characterization and density functional‐based tight‐binding calculation. The findings provide an effective strategy for modulating the charge transport through polymer dielectric engineering and also recommend a podium to further comprehend the electrical characteristics of small molecules in organic thin‐film transistors. Abstract : The bilayer polymer dielectrics are constructed by bottom‐up method, and the theoretical analysis and characterization results show that the bottom polyimide (PI) is the key to achieve band‐like transport. There is "Lego‐like" tight combination between PI and the upper polyphenylene ether, polyacrylic acid, and poly(4‐vinylphenol), which enables the devices to achieve the regulation of organic small molecule thin film FETs from the thermal activated mode to the high‐quality band‐like transport.