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A unique one‐step anodic potential step strategy has been developed recently by our group to fabricate a three‐dimensional (3D) nanoporous gold film (NPGF) within 1 min as an efficient surface‐enhanced Raman scattering (SERS) active substrate. Gloria et al. (J. Electroanal. Chem. 2011, 656, 114–119) demonstrated that the prepared NPGF under optimum conditions (2 M HCl, 50 s) has higher SERS intensities than that of a commercial single‐use gold substrate. However, the SERS performance of 3D NPGFs fabricated in neutral KCl by this strategy have not been investigated. In this paper, SERS performances of the NPGFs fabricated in electrolytes of KCl and HCl are compared for the first time, using pyridine as a test molecule. Equivalent SERS intensities can be obtained on the 3D NPGFs prepared in these two electrolytes under respectively optimum conditions. The results suggest that hot spots of nanogaps and crevices because of the aggregation/coalescence of gold nanoparticles and the formation/removal of thin gold oxide coatings contribute greatly to the high SERS activity. Copyright © 2012 John Wiley & Sons, Ltd.

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A new GaAs surface passivation method, CS2 treatment at moderate temperature was developed for effective passivation of GaAs surfaces. The CS2 treatment of GaAs surfaces at 350°C and 10 atm leads to deposition of a homogeneous film, with a thickness of several hundred Å. The passivation layer thus produced causes a significant enhancement in room temperature photoluminescence intensity and the passivation effect of the sulfide film was confirmed by Raman spectroscopy. The passivation layer remained electrically and chemically stable over a period of nine months under ambient atmospheric conditions. In-depth Auger electron spectroscopy (AES) revealed that the carbon and oxygen content in the film was negligible, whereas sulfur was uniformly distributed throughout the film. A metal-insulator-semiconductor diode whose insulating layer is produced by the CS2 treatment shows well-defined accumulation and depletion regions in its capacitance-voltage (CV) characteristics with low hysteresis.

A new GaAs surface passivation method, CS2 treatment at moderate temperature was developed for effective passivation of GaAs surfaces. The CS2 treatment of GaAs surfaces at 350 °C and 10 atm leads to deposition of a homogeneous film, with a thickness of several hundred A. The passivation layer thus produced causes a significant enhancement in room temperature photoluminescence intensity and the passivation effect of the sulfide film was confirmed by Raman spectroscopy. The passivation layer remained electrically and chemically stable over a period of nine months under ambient atmospheric conditions. In-depth Auger electron spectroscopy (AES) revealed that the carbon and oxygen content in the film was negligible, whereas sulfur was uniformly distributed throughout the film. A metal-insulator-semiconductor diode whose insulating layer is produced by the CS2 treatment shows well-defined accumulation and depletion regions in its capacitance-voltage (C-V) characteristics with low hysteresis.