Luminescent Properties of Semiconductor Photoelectrodes.
Abstract
The use of luminescent, n-type 5-1000-ppm CdS:Te and 10 ppm-CdS:Ag polycrystalline photoelectrodes as probes of recombination in photo-electrochemical cells is reported. Except for intensity, the emission spectra (lambda sub max, 600-700 nm) are insensitive to the presence of S2-/Sn2- electrolyte and to the excitation wavelengths and electrode potentials employed. With ultraband gap irradiation (lambda less than or = 500 nm) and aqueous S2-/Sn2- or Te2-/(Te2)2- electrolytes, optical energy is converted to electricity at 0.1-5% efficiency and to luminescence at 0.01-1.0% efficiency; the effects of surface preparation and grain boundaries in determining efficiency and discussed. Increasingly negative bias applied to CdS:Te and CdS:Ag photoanodes increases emission intensity by 15-100% while the photocurrent simultaneously declines to zero. Band gap edge 514.5-nm excitation yields smaller photocurrents and larger but much less potential dependent emission intensity. These results are consistent with the band bending model presently used to described photoelectrochemical phenomena. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 12, 1980
- Accession Number
- ADA089215
Entities
People
- Arthur B. Ellis
- Bradley R. Karas