Photoelectrochemical investigations on n-CdSe0.5Te0.5 thin-film electrode/polyiodide system
1998; Elsevier BV; Volume: 56; Issue: 2 Linguagem: Inglês
10.1016/s0254-0584(98)00150-3
ISSN1879-3312
AutoresV. Damodara Das, Laxmikant Damodare,
Tópico(s)Copper-based nanomaterials and applications
ResumoPolycrystalline thin films of n-CdSe0.5Te0.5 have been prepared by vacuum flash evaporation of the n-CdSe0.5Te0.5 alloy. It is found that the films are n-type and show photoactivity in a 2 M Kl + 20 mM I2 electrolyte. The films are characterized by X-ray diffraction and optical absorption studies. The optical absorption studies show the band-gap width to be ≈ 1.42 eV. Photoelectrochemical investigations have been carried out using the cell configuration n-CdSe0.5Te0.5 thin film/2 M Kl + 20 mM I2/C. Mott-Schottky plots are drawn using the space-charge capacitance data at 1 kHz frequency for various pH values of the electrolyte and are analysed to arrive at important and useful parameters. The frequency dispersion of the Mott-Schottky plots is also studied and the reasons for such behaviour are identified. The band diagram and the power output characteristics of the cell under AM1 white-light illumination are discussed. Gärtner' s model is used to calculate the minority-carrier diffusion length and the donor concentration for as-grown and photoelectrochemicaily etched films.
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