Air‐ and Active Hydrogen‐Induced Electron Trapping and Operational Instability in n‐Type Polymer Field‐Effect Transistors. (7th February 2017)

• Record Type: Journal Article
• Authors: Un, Hio‐Ieng; Zheng, Yu‐Qing; Shi, Ke; Wang, Jie‐Yu; Pei, Jian
• Is Part Of: Advanced functional materials. Volume 27:Number 11(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-02-07
• Subjects: charge trapping -- field‐effect transistors -- n‐type polymer semiconductors -- operational stability -- self‐assembly monolayers; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201605058
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract : Organic field‐effect transistors (OFETs) have attracted much attention for the next‐generation electronics. Despite of the rapid developments of OFETs, operational stability is a big challenge for their commercial applications. Moreover, the actual mechanism behind the degradation of electron transport is still poorly understood. Here, the electrical characteristics of poly{[ N, N ‐9‐bis(2‐octyldodecyl)‐naphthalene‐1, 4, 5, 8‐bis(dicarboximide)‐2, 6‐diyl]‐alt‐5, 59‐(2, 29‐bithiophene)} (P(NDI2OD‐T2)) thin‐film transistors (TFTs) as a function of semiconductor/dielectric interfacial property and environment are systematically investigated, in particular, how the copresence of water, oxygen, and active hydrogen on the surface of dielectric leads to a sharp drop‐off in threshold voltage. Evidence is found that an acid–base neutralization reaction occurring at the interface, as a combined effect of the chemical instability of dielectrics and the electrochemical instability of organic semiconductors, contributes to the significant electron trapping on the interface of P(NDI2OD‐T2) TFTs. Two strategies, increasing the intrinsic electrochemical stability of semiconductor and decreasing the chemical reactivity of gate dielectric, are demonstrated to effectively suppress the reaction and thus improve the operational stability of n‐type OFETs. The results provide an alternative degradation pathway to better understand the charge transport instability in n‐type OFETs, which is advantageous to construct high‐performance OFETs with long‐term stability. Abstract : An acid–base neutralization reaction occurring at the semiconductor/dielectric interface is found to be critical for electron trapping in n‐type organic field‐effect transistors (OFETs). Two strategies are verified to suppress the reaction and thus improve the operational stability: increasing the electrochemical stability of semiconductors and decreasing the chemical reactivity of dielectrics. These results are advantageous to construct highly stable OFETs.