KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Houngkamhang, NongluckSubject: search.filters.subject.dielectric constant

Search Results

Now showing 1 - 1 of 1
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    PMMA/High-k Self-assembled TiO2 /PMMA Multi-layer Gate Dielectric for P3HT Organic Field Effect Transistors
    (2022-01-01)
    Inpor, Kroekchai
    ;
    Houngkamhang, Nongluck
    ;
    Thanachayanont, Chanchana
    ;
    Prichanont, Seeroong
    ;
    Kayunkid, Navaphun
    In this work, a multi-layer structure of poly (methyl methacrylate)/ titanium dioxide/poly (methyl methacrylate) (PMMA/TiO₂ /PMMA; PTP) was proposed as a top-gate insulator for P3HT-based organic field-effect transistors (OFETs). Adding a TiO₂ interlayer as a high dielectric constant (high-k) material into PMMA film enables the modification of the dielectric constant of the multi-layers PTP film. The content of TiO₂ in the PTP film, which can be varied by changing the number of soaking cycles in TiO₂ solution, plays a crucial rule in modifying the dielectric constant of the PTP film. The higher the TiO₂ content used in the PTP film, the higher the dielectric constant of PTP film can be obtained. However, using high TiO₂ content led to a reduction in the dielectric constant of the PTP film due to leakage current induced by the agglomeration of TiO₂. The utilization of the top-gate insulator containing TiO₂ significantly enhanced several P3HT-OFETs characteristics, e.g., an increase in the I<inf>on</inf>/I<inf>off</inf> ratio, and a decrease in the threshold voltage. However, the use of the PTP top-gate insulator with a high content of TiO₂ resulted in regressions in the OFETs characteristics, such as a decrease in carrier mobility and reduction in the I<inf>on</inf>/I<inf>off</inf> ratio. OFETs operating at the optimum conditions of the PTP gate-insulator, with PTP thickness of 225 nm and RMS roughness of 20.0 nm, provided a dielectric constant of 7.13, a threshold voltage of-8.49 V, a saturation mobility of 2.2× 10<sup>-4</sup> cm²V<sup>-1</sup>s<sup>-1</sup>, I<inf>on</inf>/I<inf>off</inf> ratio of 37.9, and a subthreshold slope of 0.39 V/decade.