Porosity and tellurium-enrichment of anodized p-Cd0.95Zn0.05Te

In contrast to several other p-type compound semiconductors, p-Cd0.95Zn0.05 Te becomes porous by anodic treatment in acidic solution. Porous layers mor e than 100 mu m thick can be obtained by prolonged anodization in 0.5 M H2S O4. Coulometry and chemical analysis by X-ray photoelectron spectroscopy in dicate that the pore walls are covered by a film of elemental tellurium, an d the presence of this passivating film may partly explain why anodic etchi ng of the p-type material yields a porous morphology. The porosity, the tel lurium-enrichment, and their effects on the photoelectrochemical properties are discussed and compared to reports for other semiconductor materials. ( C) 1999 The Electrochemical Society. S1099-0062(99)06-138-6. All rights res erved.