Data retention ability of PVDF-TrFE as organic ferroelectric field-effect transistors

• Main Author: Yap, Wei Hao
• Other Authors: School of Materials Science and Engineering
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Materials::Organic/Polymer electronics
• Online Access: http://hdl.handle.net/10356/55855
• Institution: Nanyang Technological University

In this project, retention ability of PVDF – TrFE ferroelectric field effect transistors which utilizes either air stable PCDTBT or non-stable regioregular (rr) – P3HT as the semiconducting polymer are investigated in both air and inert environment over a period of 7 days. Field effect transistors using rr-P3HT and PCDTBT as semiconducting polymer and Cytop as the dielectric material are also investigated to understand their suitability for use in organic devices. Devices are fabricated by spin coating semiconducting material and dielectric layer followed by annealing process before evaporative deposition of gold gate metal to construct top gate bottom contact field effect transistors. Characterization techniques employed involves gate sweep and drain sweep where transfer and output characteristics of the fabricated devices are measured. Results indicated that retention ability of PVDF-TrFE ferroelectric field effect transistors are only suitable for short term nonvolatile memory functions unless leakage and charge trapping effects which are detrimental to retention ability can be eliminated. Observations also suggest that stability of semiconducting material use in organic devices do not matter if their mobility do not degrade beyond typical mobility of organic semiconductors in top gate bottom contact configuration. Further investigation pertaining to this retention mobility of non-stable organic semiconductors in organic devices needs to be done to affirm this observation.