25 August 2017 Polarization-induced transport in organic field-effect transistors: the role of ferroelectric dielectrics
Author Affiliations +
Proceedings Volume 10365, Organic Field-Effect Transistors XVI; 103650I (2017); doi: 10.1117/12.2273232
Event: SPIE Organic Photonics + Electronics, 2017, San Diego, California, United States
Abstract
The ferroelectric nature of polymer ferroelectrics such as poly(vinylidene fluoride) (PVDF) has been known for over 45 years. However, its role in interfacial transport in organic/polymeric field-effect transistors (FETs) is not that well understood. Dielectrics based on PVDF and its copolymers are a perfect test-bed for conducting transport studies where a systematic tuning of the dielectric constant with temperature may be achieved. The charge transport mechanism in an organic semiconductor often occurs at the intersection of band-like coherent motion and incoherent hopping through localized states. By choosing two small molecule organic semiconductors - pentacene and 6,13 bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) – along with a copolymer of PVDF (PVDF-TrFe) as the dielectric layer, the transistor characteristics are monitored as a function of temperature. A negative coefficient of carrier mobility is observed in TIPS-pentacene upwards of 200 K with the ferroelectric dielectric. In contrast, TIPS-pentacene FETs show an activated transport with non-ferroelectric dielectrics. Pentacene FETs, on the other hand, show a weak temperature dependence of the charge carrier mobility in the ferroelectric phase of PVDF-TrFE, which is attributed to polarization fluctuation driven transport resulting from a coupling of the charge carriers to the surface phonons of the dielectric layer. Further, we show that there is a strong correlation between the nature of traps in the organic semiconductor and interfacial transport in organic FETs, especially in the presence of a ferroelectric dielectric.
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Conference Presentation
Suchismita Guha, Amrit Laudari, "Polarization-induced transport in organic field-effect transistors: the role of ferroelectric dielectrics", Proc. SPIE 10365, Organic Field-Effect Transistors XVI, 103650I (25 August 2017); doi: 10.1117/12.2273232; http://dx.doi.org/10.1117/12.2273232
PROCEEDINGS
17 PAGES + PRESENTATION

SHARE
KEYWORDS
Dielectrics

Field effect transistors

Dielectric polarization

Transistors

Semiconductors

Interfaces

Molecules

Back to Top