Anomalous Response in Heteroacene-Based Organic Field Effect Transistors under High Pressure

Ken-Ichi Sakai,Jun Takeya

doi:10.3390/electronics3020255

Ken-Ichi Sakai, Jun Takeya

Open Access

https://doi.org/10.3390/electronics3020255

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Journal: Electronics	Publication Date: Apr 10, 2014
Citations: 10	License type: CC BY 4.0

Affiliation: The University of Tokyo

Abstract

Carrier transport properties of organic field effect transistors in dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene single crystals have been investigated under high pressure. In contrast to the typical pressure effect of monotonic increase in charge transfer rates according to the application of external hydrostatic pressure, it is clarified that the present organic semiconductor devices exhibit nonmonotonic pressure response, such as negative pressure effect. X-ray diffraction analysis under high pressure reveals that on-site molecular orientation and displacement in the heteroacene molecule is assumed to be the origin for the anomalous pressure effects.

Highlights

Organic molecular solids, such as organic semiconductors, have been studied intensively due to their considerable scientific and industrial uses
X-ray diffraction (XRD) experiments were carried out using well-purified DNTT powder by a synchrotron radiation source on the beamline BL10XU at SPring-8 in order to have an idea of change in unit cells in high pressure
The giant pressure effect with extreme pressure response up to 3.8 GPa−1 is attributed to the widely-distributed 3pz orbital localized on sulfur atoms

Summary

Introduction

Organic molecular solids, such as organic semiconductors, have been studied intensively due to their considerable scientific and industrial uses. Considerable impact is expected with the application of external pressure, by reducing molecular distance and by deforming the crystal structure due to freedom of onsite molecular orientation. This is essentially different from inorganic semiconductors composed of atoms which appear as a spherical mass point. The application of external pressure is expected to induce a striking change in simple reduction of intermolecular molecule distance, and the deformation of the crystal structure due to the freedom of onsite molecular orientation, and the unanticipated pressure response of electronic properties unlike a simple linear increase in charge transfer rate. In combination with the measurement of anisotropic charge transfer and structural studies, a route to study the so-called “structure-property relations” is provided [9]

Preparation of Single-Crystal Organic Semiconductor

Carrier Transport Measurement under High Pressure

Structural Analysis

Results and Discussion

Conclusions