AS(2)S(3) and AgI thin layers as ion sensitive membranes

The possibilities of using thin layers of As2S3 and AgI as ion sensitive me mbranes for ion selective field-effect transistors (ISFETs) are investigate d. The thin films have been prepared by vacuum deposition on static and rot ating substrates. The As2S3 layers were additionally doped with silver. The influence of the type of substrates and preparation conditions on electroc hemical properties of the layers was studied. Electrochemical measurements revealed a reasonable sensitivity of chalcogenide and halide layers to silv er and iodide ions, respectively. The near Nernstian behavior of sensitivit y of As2S3 layers to Ag+ ions and of AgI layers to I- ions is observed. The results obtained are promising for the development of ISFETs. (C) 1999 Els evier Science B.V. All rights reserved.