title: Investigation of extended-gate field-effect transistor pH sensors based on different-temperature-annealed bi-layer MWCNTs-In2O3 films.
abstract: In this paper, indium (In) films were deposited on glass substrates using DC sputtering method. Multiwalled carbon nanotubes (MWCNTs) and dispersant were dissolved in alcohol, and the mixed solution was deposited on the In films using the spray method. The bi-layer MWCNTs-In2O3 films were annealed at different temperatures (from room temperature to 500°C) in O2 atmosphere. The influences of annealing temperature on the characteristics of the bi-layer MWCNTs-In2O3 films were investigated by scanning electron microscopy, X-ray diffraction pattern, Fourier transform infrared (FT-IR) spectroscopy, and Raman spectroscopy. A separative extended-gate field-effect transistor (EGFET) device combined with a bi-layer MWCNTs-In2O3 film was constructed as a pH sensor. The influences of different annealing temperatures on the performances of the EGFET-based pH sensors were investigated. We would show that the pH sensitivity was dependent on the thermal oxygenation temperature of the bi-layer MWCNTs-In2O3 films.
authors.affiliation: Department of Information Technology & Communication, Shih Chien University Kaohsiung Campus, Neimen, Kaohsiung 84550, Taiwan, R.O.C.
authors.forename: Shang-Chao
authors.initials: SC
authors.lastname: Hung
authors.affiliation: Institute of Photonics and Communications, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan, R.O.C.
authors.forename: Nai-Jen
authors.initials: NJ
authors.lastname: Cheng
authors.affiliation: Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 81147, Taiwan, R.O.C.
authors.forename: Cheng-Fu
authors.initials: CF
authors.lastname: Yang
authors.affiliation: Graduate Institute of Electro-Optical Engineering and Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 10608, Taiwan, R.O.C.
authors.forename: Yuan-Pin
authors.initials: YP
authors.lastname: Lo
keywords: Bi-layer; MWCNTs-In2O3 films; Multiwalled carbon nanotubes; pH sensor