Sd. Babenko et al., THE EFFECT OF ILLUMINATION INTENSITY ON THE KINETICS OF HYDROGEN EVOLUTION AT P-TYPE SILICON, Russian journal of electrochemistry, 33(2), 1997, pp. 212-214
The effect of illumination intensity on the kinetics of hydrogen photo
generation is studied experimentally at the silicon electrode in acid
solutions. The charge-transfer and surface-recombination rate constant
s are found to increase with the light intensity. This effect is expla
ined by a decrease in the band bending near the semiconductor surface
and a corresponding change in the potential drop across the Helmholtz
layer, both effects being due to accumulation of a photoelectron charg
e at the semiconductor surface. For a light intensity of 1.5 mW cm(-2)
, the change in the band bending amounts to ca. 0.2 eV, which results
in a nearly tenfold increase of the pertinent rate constants.