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Title: Effect of reduction of trap charge carrier density in organic field effect transistors by surface treatment of dielectric layer

Journal Article · · Journal of Applied Physics
DOI:https://doi.org/10.1063/1.4842856· OSTI ID:22266168
; ; ; ;  [1];  [1]
  1. Physics of Energy Harvesting Division, CSIR-National Physical Laboratory, CSIR-Network of Institute for Solar Energy (NISE), Dr. K.S.Krishnan Road, New Delhi 110012 (India)

In this work, we have studied the effect of surface treatment of SiO{sub 2} dielectric layer on the reduction of the trap charge carrier density at dielectric/semiconducting interface by fabricating a metal–insulator–semiconductor (MIS) device using α, ω-dihexylcarbonylquaterthiophene as semiconducting layer. SiO{sub 2} dielectric layer has been treated with 1,1,1,3,3,3-hexamethyldisilazane (HMDS) to modify the chemical group acting as charge traps. Capacitance-voltage measurements have been performed on MIS devices fabricated on SiO{sub 2} and HMDS treated SiO{sub 2}. These data have been used for the calculation of trap charge carrier density and Debye length at the dielectric-semiconductor interface. The calculated trap charge carrier density has been found to reduce from (2.925 ± 0.049) × 10{sup 16} cm{sup −3} to (2.025 ± 0.061) × 10{sup 16} cm{sup −3} for the MIS device with HMDS treated SiO{sub 2} dielectric in comparison to that of untreated SiO{sub 2}. Next, the effect of reduction in trap charge carrier density has been studied on the performance of organic field effect transistors. The improvement in the device parameters like mobility, on/off ratio, and gate leakage current has been obtained with the effect of the surface treatment. The charge carrier mobility has been improved by a factor of 2 through this treatment. Further, the influence of the treatment was observed by atomic force microscope and Fourier transform infrared spectroscopy techniques.

OSTI ID:
22266168
Journal Information:
Journal of Applied Physics, Vol. 114, Issue 22; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
Country of Publication:
United States
Language:
English