2009 APS March Meeting
Volume 54, Number 1
Monday–Friday, March 16–20, 2009;
Pittsburgh, Pennsylvania
Session J18: Charge Transport and Optical Properties of Organic Semiconductors
11:15 AM–2:15 PM,
Tuesday, March 17, 2009
Room: 319
Sponsoring
Units:
DMP DPOLY
Chair: Markus Wohlgenannt, University of Iowa
Abstract ID: BAPS.2009.MAR.J18.1
Abstract: J18.00001 : Light Emitting Transistors of Organic Single Crystals
11:15 AM–11:51 AM
Preview Abstract
Abstract
Author:
Yoshihiro Iwasa
(Tohoku University)
Organic light emitting transistors (OLETs) are attracting
considerable
interest as a novel function of organic field effect transistors
(OFETs).
Besides a smallest integration of light source and current switching
devices, OLETs offer a new opportunity in the fundamental
research on
organic light emitting devices. The OLET device structure allows
us to use
organic single crystals, in contrast to the organic light
emitting diodes
(OLEDs), the research of which have been conducted predominantly on
polycrystalline or amorphous thin films. In the case of OFETs,
use of single
crystals have produced a significant amount of benefits in the
studies of
pursuit for the highest performance limit of FETs, intrinsic
transport
mechanism in organic semiconductors, and application of the
single crystal
transistors.
The study on OLETs have been made predominantly on
polycrystalline films or
multicomponent heterojunctions, and single crystal study is still
limited to
tetracene [1] and rubrene [2], which are materials with
relatively high
mobility, but with low photoluminescence efficiency. In this
paper, we
report fabrication of single crystal OLETs of several kinds of
highly
luminescent molecules, emitting colorful light, ranging from blue
to red.
Our strategy is single crystallization of monomeric or oligomeric
molecules,
which are known to have a very high photoluminescence efficiency.
Here we
report the result on single crystal LETs of rubrene (red),
4,4'-bis(diphenylvinylenyl)-anthracene (green),
1,4-bis(5-phenylthiophene-2-yl)benzene (AC5) (green), and
1,3,6,8-tetraphenylpyrene (TPPy) (blue), all of which displayed
ambipolar
transport as well as peculiar movement of voltage controlled
movement of
recombination zone, not only from the surface of the crystal but
also from
the edges of the crystals, indicting light confinement inside the
crystal.
Realization of ambipolar OLET with variety of single crystals
indicates that
the fabrication method is quite versatile to various light emitting
molecular solids, providing novel opportunities to get further
insight on
the intrinsic optoelectronic processes in organic semiconductors.
\\[4pt]
[1] T. Takahashi et al., Adv. Funct. Mater. 17, 1623 (2007).\\[0pt]
[2] T. Takenobu et al., Phy. Rev. Lett. 100, 066601 (2008).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.MAR.J18.1