Fabrication and application of a novel four-terminal hybrid organic/inorganic field-effect transistor for volatile organic compounds sensing

The potential application of a novel hybrid organic/inorganic volatile organic compounds sensor for commercialization and scientific research is presented. This sensor can operate both in the commonly used ‘organic thin-film transistor’ (OTFT) and ‘chemical field-effect transistor’ (CHEMFET) sensing modes as well as in a new, potentially useful sensing mode, referred to as ‘chemical memory’ mode. Compared to existing commercially available sensors, organic thin-film transistors (OTFT) show promising advantages of being cheap and easy to manufacture, light and portable, and easy to integrate in electrical circuits. However, OTFTs still operate at high voltages and lack sensitivity. This thesis will present the OTFT with patterned gate, which will eliminate the restrictions common OTFTs face. With this approach increased sensing responses are achieved. Furthermore, the sensor can be operated at low voltages such as 1V, making them extremely interesting for portable sensor devices. Comparisons with regard to their sensing responses of CuPc and pentacene organic thin-film transistors with different growth conditions are given as well. Additionally, the charge trapping mechanisms occurring during the sensing events are investigated. It is found that the charge mobilities are drastically reduced by more than 1/7 of their initial values, whereas the threshold voltages are only slightly affected. The threshold voltage can be independently evaluated by both the OTFT and ‘chemical memory’ modes.

Name thesis:degree_name

Master of Arts

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Physics

Grantor

University of Texas at Austin

Year dc:date.issued

2007

Author dc:creator

• Schoefer, Sebastian Paul

Advisor dc:contributor.advisor

• Dodabalapur, Ananth, 1963-

• Organic thin film transistor based sensors
• Sensing responses
• Organic semiconductors

Statement dc:rights

• Copyright © is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.

Language dc:language.iso

eng

Identifier URI

http://dx.doi.org/10.26153/tsw/1446

OAI identifier oai:identifier

oai:repositories.lib.utexas.edu:2152/74326