Multicomponent Organic Thin Film Transistors

Open Access
Author:
Lee, Taesup
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Enrique Daniel Gomez, Thesis Supervisor
  • Darrell Velegol, Honors Advisor
Keywords:
  • Organic field electron transistor
  • mobility
  • transistor
  • P3HT
Abstract:
Different materials exhibit different properties when testing for electron and electron hole mobility. Electron mobility measures the ease with which charge can move from one place to another. Various materials were coated onto transistors and the electron mobility was determined for the different materials. Poly(3-hexylthiophene) (P3HT) is a common material used in field-effect transistors, and was the polymer used in this study. P3HT was mixed with the molecule 3,3”-didodecyl-2,2’:5’,2”:5”,2”’ quaterthiophene in hopes of achieving a higher electron mobility for the mixture than those of the polymer and molecule individually. Using silicon substrates, spin coaters, and solar device testers, the hypothesis was tested. The hypothesis tested here was that a polymer-molecule mixture would exhibit higher electron mobility values compared to the mobilities of the pure polymer and molecule components separately. Through changing certain variables, the optimum conditions to achieve the highest mobility were found to be using trichlorobenzene as the solvent, and annealing the substrate before testing at 150ºC. Using these conditions, P3HT was found to have a mobility of 1.53×10-3 cm2/(V*s), the quaterthiophene molecule, a mobility of 5.94×10-4 cm2/(V*s), and a 50-50 weight percent mixture of P3HT and quaterthiophene a mobility of 7.67×10-3 cm2/(V*s). Based on these results, mixing a polymer and a molecule yielded a mixture with better electron mobility characteristics than the polymer or molecule by itself.