Determination of the characteristics of a Schottky barrier formed by latent finger mark corrosion of brass

作者：Bond J W^*

来源：Journal of Physics D: Applied Physics , 2009, 42(23): 235301.

DOI：10.1088/0022-3727/42/23/235301

The ideality factor (eta) and barrier height (phi(B)) for a metal-copper(I) oxide rectifying contact formed by the latent finger mark corrosion of alpha phase brass have been determined from forward bias I/V characteristics in the range 0.4V <= V <= 0.55 V. Rectifying contacts formed from the finger mark deposits of different people gave eta = 1.5-1.6 +/- 0.1 and phi(B) = 0.49-0.52 +/- 0.04V. A Mott-Schottky plot of capacitance-voltage measurements in reverse bias gave the built in potential psi(bi) = 0.4 +/- 0.1V, the gradient of the plot confirming the conductivity of the finger mark corrosion as p type. X-ray photoelectron spectroscopy spectra of the corrosion showed that Cu(I), Cu(II) and Zn(II) can co-exist on the surface, the Cu(I) : Cu(II) and Zn : Cu ratios determining whether a rectifying contact is formed. Initial findings suggest that when the concentration of Cu(I) dominates the Cu(I) : Cu(II) ratio (approximately 6 : 1), or when Cu(II) is absent, a rectifying contact can be formed subject to the Zn : Cu ratio being approximately 1:3. As the surface concentration of zinc increases, the rectifying contact is degraded until the concentration of zinc approaches that of copper when no evidence of a Schottky barrier is observed and the contact appears ohmic.

• 出版日期2009-12-7