OBSERVATION OF DEVIATION OF ELECTRONIC BEHAVIOR OF INDIUM TIN OXIDE FILM AT GRAIN-BOUNDARY USING SCANNING TUNNELING MICROSCOPE

Scanning Tunneling Microscopy and Spectroscopy investigations have bee n carried out on electron beam deposited indium tin oxide films. The S TM images reveal a rather smooth surface, which appears to have been f ormed due to the coalescence of islands with different shapes. The spe ctroscopic data, in general, exhibit characteristics typical of metal- insulator-semiconductor structures, with a heavily doped semiconductor . From the I-V curves, a band gap of approximate to 3.5 eV is obtained , which is very close to the bulk value. The I-V studies at some grain boundary interfaces suggest the presence of regions showing electroni c characteristics, that differ significantly from what is observed on the rest of the film surface. (C) 1997 Elsevier Science Ltd.