Effects of contact treatments on solution-processed n-type dicyano-ovalenediimide and its complementary circuits

Abstract

The device performance of bottom-contact organic field-effect transistors (OFETs) was limited by contact resistance which originates from a non-optimal semiconductor growth morphology and limited charge injection area. Self-assembled monolayer (SAM) treatment has proved to be an effective approach to optimize thin film growth and align the energy levels. This SAM-induced work-function modification has different effects on the charge injection barrier as well as on the device performance in terms of threshold voltage. These results were analysed in detail from the perspectives of surface morphology and energy alignment at the Au-semiconductor interface in n-type ovalenediimide (ODI-CN)-based OFETs. Finally, complementary inverters were built using pentacene (p-type) and ODI-CN (n-type) OFETs, and these showed a voltage gain of 13.

Reduced Threshold Voltages and Enhanced Mobilities in Diketopyrrolopyrrole–Dithienothiophene Polymer‐Based Organic Transistor by Interface Engineering

“…The BG–BC device configuration is more suitable and appropriate because of its simplicity of fabrication and compatibility with mass production of organic transistors using established lithographic processes. [ 5 ] The BG–BC configuration is also beneficial from the fact that the charge injection area in the BG–BC configuration is directly exposed to the sensing analytes, thus, increasing the extent of sensitivity. [ 50 ] Figure a shows molecular structures PDPPT–DTT polymer used for the OFET device interface engineering study.…”

“…The low‐voltage operating solution processable organic field‐effect transistors (OFETs) are basic building blocks of flexible electronics that have attracted remarkable interest across different application areas, such as organic ferroelectric memory, [ 1–3 ] chemical sensors, [ 4 ] integrated circuits, [ 5,6 ] wearable sensors, [ 7 ] and robotics. [ 8 ] Molecular approaches to enhance OFET mobility have been very successful and OFETs’ mobilities have now surpassed amorphous silicon‐based thin film transistors (TFTs).…”

“…There have been substantive studies related to efficient injection of charge carriers from the respective source–drain (S–D) electrodes into organic semiconductor channel region. [ 5,21,32,33 ] Pentafluorobenzene thiol (PFBT) treatment has been one of the most widely used metal interface modifying SAM material. [ 34–37 ] Most recently, OFET's electrical characteristics variation under the presence of interface modifications done simultaneously at both barriers, for a given organic semiconductor material, has emerged as a promising approach.…”

N,N′-Dihydrotetraazapentacenes (DHTA) in thin film transistors

“…These values are rather high for a traditional p-type semiconductor, however, reasonable hole injection from pentauoro-benzenethiol (PFBT, pen-tauorothiophenol) modied Au electrodes (work function 5.4 eV) can be achieved. 27 Thin lm transistor performance Fig. 4 shows the top gate/bottom contact transistor architecture we used to characterise the charge transport properties of our materials.…”

Low-temperature sol–gel processed AlOx gate dielectric buffer layer for improved performance in pentacene-based OFETs

“…Traditionally, 200 nm to 300 nm thick commercially available or home made silicon oxide (SiO 2 ) lm, thermally grown on a heavily doped n or p type silicon (Si) substrate is used as gate dielectric in OFETs. [7][8][9] The k value for SiO 2 is <4.0. This presents SiO 2 as a low capacitance gate dielectric material which yields an OFET with low performance.…”