Effect of temperature on rectifying Schottky barriers formed from fingerprint sweat corrosion of brass.

Corrosive electrochemical processes of brass, including those resulting from fingerprint sweat, continue to be studied because of the widespread industrial use of brass. Here, we examine how increased temperature affects the relative abundance of fingerprint sweat corrosion products and the rectifying Schottky barrier formed between p-type copper (I) oxide corrosion and brass. X-ray photoelectron spectroscopy confirms increasing dezincification with increasing temperature. This leads to n-type zinc oxide replacing copper (I) oxide as the dominant corrosion product, which then forms a rectifying Schottky barrier with the brass, instead of copper oxide, when the temperature reaches c. 600°C. Using X-ray diffraction, resulting diodes show polycrystalline oxides embedded in amorphous oxidation products that have a lower relative abundance than the diode forming oxide. Conventional current/voltage (I/V) characteristics of these diodes show good rectifying qualities. At temperatures between c. 100 and c. 600°C, when neither oxide dominates, the semiconductor/brass contact displays an absence of rectification.