PH-Sensitive Ni(OH)2-Based Microelectrochemical Transistors.
Abstract
Properties of arrays of closely spaced (1.2 micron) Au or Pt microelectrodes (approx. 2 micron wide x 50 micron long x 0.1 micron high) coated with cathodically grown films of Ni(OH)2 are reported. Electrical connection of microelectrodes by Ni(OH)2 was verified by cyclic voltammetry. The ratio of anodic charge to cathodic charge in cyclic voltammograms for the Ni(OH)2 = NiO(OH) interconversion exceeds one. However, it is shown that excess charge in the anodic cyclic voltammetric wave for oxidation of Ni(OH)2 does not affect the conductivity of Ni(OH)2 films. The steady state resistance of Ni(OH)2 connecting two microelectrodes has been measured as a function of potential from 0 V to 0.7 V vs. SCE, and was typically found to vary from approx. 10 to the minus 7th power to approx. 0.0001 ohms. The measured resistance corresponds to a resistivity of approximately 30 ohm-cm in the oxidized state. The decrease in resistance is caused by electrochemical oxidation of insulating Ni (OH)2 to conducting NiO (OH). At fixed drain voltage, VD, the gate current, IG, and the drain current, ID, can be measured simultaneously as the gate voltage, VG, is varied at a given frequency.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 24, 1986
- Accession Number
- ADA174679
Entities
People
- D. Belanger
- M. K. Carpenter
- Mark S. Wrighton
- Michael J. Natan
Organizations
- Massachusetts Institute of Technology