Analysis of CapacitancePotential Measurements at the Silicon−Electrolyte Interface Revisited

• Published in: Journal of physical chemistry. C 2007-04, Vol.111 (14), p.5497-5499
• Main Authors: Allongue, P., Chazalviel, J.-N., Henry de Villeneuve, C., Ozanam, F.
• Format: Article
• Language: English
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp068614z

The analysis of the capacitance−potential curves is revisited by using a more accurate bias dependence of the silicon space charge layer capacitance (C SC) under accumulation conditions (Tardella, A.; Chazalviel, J.-N. Phys. Rev. B 1985, 32, 2439). In the case of a well-defined stepped H-terminated Si(111) surface, we show that the improved analysis yields a more realistic C H value:  ∼8 μF/cm2 (∼3.5 μF/cm2 was derived from the Poisson−Boltzmann analysis). However, in the case of samples grafted with organic chains, we show that the model used for C SC has no influence on the determination of the effective dielectric constant εEFF of the organic layer.