Determination of the Wavelength-Dependent Refractive Index of a Gold-Oxide Thin Film

Gold oxide as a protecting group for regioselective surface chemistry

“…These binding energies are similar to those reported for gold oxide grown by pulsed-laser deposition and are consistent with a mixed oxide containing both oxo and hydroxyl species. [28][29][30]33,34 The ratio of Au 3+ to oxygen on this sample was 38 : 62, very close to that expected for Au 2 O 3 (40 : 60).…”

“…Ellipsometry also indicated the continued presence of the oxide coating. 34 High-resolution XPS spectra in the Au 4f region verified that electrode 2 remained in a reduced state after this step (Fig. S1, ESIw).…”

Relative lability of gold-oxide thin films in contact with air, solvents, or electrolyte solutions

“…[7][8][9][10]26 The presence of an oxide was confirmed by the appearance of a large cathodic wave in a linear sweep of potential in 0.5 M sulfuric acid, corresponding to reduction of the oxide to the metal (Fig. [7][8][9][10]26 The presence of an oxide was confirmed by the appearance of a large cathodic wave in a linear sweep of potential in 0.5 M sulfuric acid, corresponding to reduction of the oxide to the metal (Fig.…”

“…26 The software solves for a consistent thickness of gold oxide corresponding to the measured values of W and D for each sample. Woollam V-VASE variable angle spectroscopic ellipsometer.…”

“…19 Measurements of surface resistance on thicker films (>40 Å ) gave a lower activation energy for the decomposition of Au 2 O 3 (57 kJ/mol) and a half-life at 22 C of 22 h. 20 This difference may reflect nonlinearity in the relationship between surface resistance and composition or reduction of the film by primary and secondary electrons generated by exposure to x rays during analysis by x-ray photoelectron spectroscopy in the latter study. 26 We were prompted by these studies to examine the relative lability of these films in contact with air and with various condensed phases in order to determine under what conditions they would remain intact. [22][23][24][25] We recently showed that thin films of gold oxide can be used as passivation layers to allow selective reactivity on a particular gold electrode in the presence of another.…”