Humidity-voltaic characteristics of Au-porous silicon interfaces


Dzhafarov T., Oruç Ç. , Aydin S.

JOURNAL OF PHYSICS D-APPLIED PHYSICS, vol.37, no.3, pp.404-408, 2004 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 37 Issue: 3
  • Publication Date: 2004
  • Doi Number: 10.1088/0022-3727/37/3/016
  • Title of Journal : JOURNAL OF PHYSICS D-APPLIED PHYSICS
  • Page Numbers: pp.404-408

Abstract

The humidity-voltaic effect, i.e. generation of open-circuit voltage (V,,c), in Au-porous silicon (PS) interface in humid atmosphere (up to 450 mV at 95% relative humidity) in dark and daylight illumination is discovered. The humidity-stimulated voltage generation is attributed to the splitting of water and hydrogen molecules on the surfaces of the Au catalyst, where further diffusion penetration of hydrogen ions into the Au-PS interface results in the formation of dipoles, thus inducing V-oc across dipoles. The generation of Voc (up to 550 mV) has also been observed on dipping of Au-PS structures in different hydrogen-containing solutions (ethanol, benzine, sodium tetraborate pentahydrate, etc). Data of response time-dependent changes of the open-circuit voltage generated in Au-PS structures under humid conditions were used for the estimation of diffusion coefficients of hydrogen. The temperature dependence of the diffusion coefficient of hydrogen at 323-353 K via the pore surfaces of PS is attributed to be D = 1.3 x 10(-2) exp(-0.25/kT).