Phenanthrene Condensed Thiadiazoloquinoxaline Donor–Acceptor Polymer for Phototransistor Applications

Abstract

A novel donor-acceptor polymer, PPhTQ, is synthesized by condensing a phenanthrene unit onto a thiadiazoloquinoxaline moiety. This polymer shows a broad absorption band from visible to near infrared and a very low optical bandgap of 0. 80 eV. A well-balanced ambipolar field-effect behavior is observed for PPhTQ, with mobilities of 0.09 cm 2 V-1 s-1 for holes and 0.06 cm 2 V-1 s-1 for electrons. A two-dimensional charge carrier transport in the film is determined by low-temperature resistance measurements, and an ordered face-on organization is found by grazing incidence wide-angle X-ray scattering. More importantly, a PPhTQ thin film phototransistor exhibits an excellent device performance with a maximum photoresponsivity of 400 A/W.

Ambipolar organic phototransistors based on 6,6′-dibromoindigo

“…Phototransistors based on ambipolar materials, which are single component systems that can function as both p-and n-type semiconductors, have also been demonstrated. [24][25][26][27] Single component, ambipolar transistors are cost-effective and boast several advantages including largearea applicability and simple fabrication. Despite their advantages, research on ambipolar material-based phototransistors is insufficient.…”

Bulk- and layer-heterojunction phototransistors based on poly [2-methoxy-5-(2′-ethylhexyloxy-p-phenylenevinylene)] and PbS quantum dot hybrids

“…The regular-shaped interface has two influences, being good for carrier transport (improved order degree of channel) but being harmful to charge separation (b is as low as À0.18). The MEH-PPV hole mobility is of the order of 10 À2 -10 À6 cm 2 V À1 s À1 , 28,31 while that of the QD FET is $10 cm 2 V À1 s À1 , 7 indicating that the holes in the QD layer are transported more effectively than in MEH-PPV. Thus, the measured mobility (36 cm 2 V À1 s À1 ) is mainly the contribution of the hole transport in the QD layer, and is also a reasonable value for mobility in QD FETs, according to a previous report.…”

“…[26][27][28] However, traditional field effect transistor (FET) theory is always applied to QD FETs. 7 The transfer characteristics of the two types of hybrid FEpT are closer to the representative curves of QD FETs, and thus traditional FET theory applies to the hybrid devices.…”

Controlling the Surface Organization of Conjugated Donor–Acceptor Polymers by their Aggregation in Solution

“…Semiconducting polymers show potential for applications in organic field‐effect transistors (OFET) due to their advantages in lightweight, mechanical flexibility, and solution processability compared with inorganic semiconductors . Solution processing, as the only possibility for thin‐film deposition of conjugated polymers, offers opportunities to affect the charge‐carrier mobility in OFET devices, because of its fine control over the semiconductor microstructure and molecular ordering that play a critical role in the charge‐carrier transport .…”