Lateral solidification of a liquid crystalline semiconductor film induced by temperature gradient

Tomoya Hoshino; Hayato Ito; Ichiro Fujieda; Tomonori Hanasaki

doi:10.1117/12.2022494

18 September 2013 Lateral solidification of a liquid crystalline semiconductor film induced by temperature gradient

Tomoya Hoshino, Hayato Ito, Ichiro Fujieda, Tomonori Hanasaki

Proceedings Volume 8831, Organic Field-Effect Transistors XII; and Organic Semiconductors in Sensors and Bioelectronics VI; 883115 (2013) https://doi.org/10.1117/12.2022494
Event: SPIE Organic Photonics + Electronics, 2013, San Diego, California, United States

Abstract

Derivatives of [1]benzothieno[3,2-b]benzothiophene (BTBT) are attracting much attention as a highly soluble, highmobility semiconductor material for thin-film transistor applications. These small molecules are known to organize themselves into a single crystalline structure after spin coating or drop casting. Charge transport in a single crystal material is anisotropic in nature. Hence, it is desired to control its orientation during growth or recrystallization so that the source and drain electrodes of a transistor are to be placed along a faster transport direction. We propose to generate temperature gradient in a heated liquid crystalline thin film to induce lateral recrystallization. In experiment, we tried two methods. First, an aluminum plate with two narrow ridges was inserted between a temperature-controlled stage and a square silicon substrate with a 200nm-thick SiO₂ and a spin-coated C₈-BTBT film. We raised the temperature of the stage to 120oC and let it cool gradually. During cooling at around 105oC , the color of the sample started to change, indicating a phase change. This change proceeded from the corners of the film and in about 30 seconds, darker regions merged at the center of the substrate. Second, the sample was placed at the edge of the stage. In this case, the color change started from the protruding corner of the sample and proceeded toward the other end. Micrograph observation revealed that cracks were formed in these films and they were perpendicular to the direction of the phase change.

Citation Download Citation

Tomoya Hoshino, Hayato Ito, Ichiro Fujieda, and Tomonori Hanasaki "Lateral solidification of a liquid crystalline semiconductor film induced by temperature gradient", Proc. SPIE 8831, Organic Field-Effect Transistors XII; and Organic Semiconductors in Sensors and Bioelectronics VI, 883115 (18 September 2013); https://doi.org/10.1117/12.2022494

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available