High mobility ambipolar organic field-effect transistors with a nonplanar heterojunction structure

Jui Fen Chang, Wei Ren Chen, Sheng Miao Huang, Yi Chien Lai, Xuan You Lai, Yaw Wen Yang, Chia Hsin Wang

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Ambipolar organic field-effect transistors (OFETs) based on a bilayer structure of highly crystalline small molecules, n-type α,ω-diperfluorohexylquaterthiophene (DFH-4T) and p-type dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT), are investigated. By employing DFH-4T/DNTT as the bottom/top layers and appropriate high work function (WF) electrodes in a bottom-gate, top-contact configuration, the superior ambipolar characteristics with matched electron and hole mobilities of 1-1.1 cm2 V-1 s-1 are achieved. Intriguingly, this high-performance device exhibits a unique feature of an extremely rough, nonplanar heterojunction in the DFH-4T/DNTT combination and a large electron injection barrier from the high WF electrodes to DFH-4T, suggesting some underlying mechanisms for the effective charge transport and injection. The electrical and structural analyses reveal that the crystal packing of the bottom DFH-4T layer supports the growth of a high-quality DNTT crystal network for high-mobility hole transport upon the nonplanar heterojunction, and also enables the formation of an enlarged organic/metal contact surface for efficient electron injection from the high WF electrodes, as the key attributes leading to an overall excellent ambipolar behavior. The effect of intrinsic charge accumulation at the heterojunction interface on the ambipolar conduction is also discussed. Furthermore, a complementary-like inverter constructed with two DFH-4T/DNTT ambipolar OFETs is demonstrated, which shows a gain of 30.

Original languageEnglish
Pages (from-to)84-91
Number of pages8
JournalOrganic Electronics
Volume27
DOIs
StatePublished - 1 Dec 2015

Keywords

  • Ambipolar
  • Organic transistors

Fingerprint

Dive into the research topics of 'High mobility ambipolar organic field-effect transistors with a nonplanar heterojunction structure'. Together they form a unique fingerprint.

Cite this