Conjugated polymer/paraffin blends for organic field-effect transistors with high environmental stability

AbstractPhotoactive organic field-effect transistors, photOFETs, based on a conjugated polymer/fullerene blend, MDMO-PPV: PCBM (1:4), and polymeric dielectrics as polyvinylalcohol (PVA) or divinyltetramethyldisiloxane-bis(benzocyclobutene) (BCB) with top source and drain electrodes were fabricated and characterized in dark and under AM1.5 illumination. With LiF/Al as top source and drain contacts the devices feature n-type transistor behavior in dark with electron mobility of 10-2cm2/Vs. Under illumination, a large free carrier concentration from photo-induced charge transfer at the polymer/fullerene bulk heterojunction (photodoping) is created. The device performance was studied with different illumination intensities and showed to be strongly influenced by the nature of the organic dielectric/organic semiconductor interface resulting in phototransistor behavior in BCB-based photOFETs and in phototransistor or photoresistor behavior for PVA-based photOFETs.

Download Full-text

Enhanced Environmental Stability Induced by Effective Polarization of a Polar Dielectric Layer in a Trilayer Dielectric System of Organic Field-Effect Transistors: A Quantitative Study

ACS Applied Materials & Interfaces ◽

10.1021/am507636k ◽

2015 ◽

Vol 7 (3) ◽

pp. 1915-1924 ◽

Cited By ~ 33

Author(s):

Nimmakayala V. V. Subbarao ◽

Murali Gedda ◽

Parameswar K. Iyer ◽

Dipak K. Goswami

Keyword(s):

Quantitative Study ◽

Dielectric Layer ◽

Field Effect ◽

Field Effect Transistors ◽

Environmental Stability ◽

Organic Field Effect Transistors ◽

Polar Dielectric ◽

Dielectric System ◽

Effective Polarization

Download Full-text

Bandgap Engineering of an Aryl-Fused Tetrathianaphthalene for Visible-Blind Organic Field-Effect Transistors

Frontiers in Chemistry ◽

10.3389/fchem.2021.698246 ◽

2021 ◽

Vol 9 ◽

Author(s):

Lijuan Zhang ◽

Xinzi Tian ◽

Yantao Sun ◽

Jiarong Yao ◽

Shuyuan Yang ◽

...

Keyword(s):

Field Effect ◽

Large Scale ◽

Near Infrared ◽

Field Effect Transistors ◽

Ambient Air ◽

Operational Stability ◽

Environmental Stability ◽

Organic Field Effect Transistors ◽

Major Barrier ◽

Visible Blind

Stability problem of organic semiconductors (OSCs) because of photoabsorption has become a major barrier to large scale applications in organic field-effect transistors (OFETs). It is imperative to design OSCs which are insensitive to visible and near-infrared (VNIR) light to obtain both environmental and operational stability. Herein, taking a 2,3,8,9-tetramethoxy [1,4]benzodithiino[2,3-b][1,4]benzodithiine (TTN2) as an example, we show that controlling molecular configuration is an effective strategy to tune the bandgaps of OSCs for visible-blind OFETs. TTN2 adopts an armchair-like configuration, which is different from the prevailing planar structure of common OSCs. Because of the large bandgap, TTN2 exhibits no photoabsorption in the VNIR region and OFETs based on TTN2 show high environmental stability. The devices worked well after being stored in ambient air, (i.e. in the presence of oxygen and water) and light for over two years. Moreover, the OFETs show no observable response to light irradiation from 405–1,020 nm, which is also favorable for high operational stability.

Download Full-text