Photoluminescent Response of Palladium-Cadmium Sulfide and Palladium-Graded Cadmium Sulfoselenide Schottky Diodes to Molecular Hydrogen

摘要

The bulk photoluminescence (PL) of Schottky diodes constructed from Pd and n-type CdS (Pd-CdS) and from n-type, graded CdSxSe1-x (0 less than or = x less than or = 1; x - 1 at surface) (Pd-CdSxSe1-x) is sensitive to molecular H2. For the Pd-CdS diode, exposure to H2 (3:1, N2:H2 mixture) significantly enhances the PL intensity of edge emission lambda max approx. 510 nm) relative to the intensity in air; using a dead-layer model, the corresponding reductions in depletion width and Schottky barrier height can be estimated. For the Pd-CdSxSe1-x dioded, H2 changes the spectral distribution; PL from this material, color-coded to spatially resolve e(-)-h(+) pair recombination, indicates the depth over which the electric field is reduced in the semiconductor. These phenomenal demonstrate optically-coupled chemical sensing of hydrogen. (Author)