B. Pashmakov et al., TRANSPORT NEAR THE MOBILITY EDGE, THE SIGN OF THE HALL-EFFECT, PHOTOREDUCTION AND OXIDATION OF AMORPHOUS INO-CHI, Journal of non-crystalline solids, 166, 1993, pp. 441-444
The electronic transport properties of amorphous indium oxide (a-InOx)
are studied as samples are changed reversibly between semiconducting
and metallic states by photoreduction and reoxidation. Photons with hv
greater than or equal to 3.5eV produce conducting states in which hol
es are self-trapped presumably in weak O-O bonds. Screening induces a
nonmetal-metal transition at high electron concentrations n, while at
lower n the temperature dependence of the conductivity follows the Mey
er-Neldel rule with parameters nearly identical to hydrogenated amorph
ous silicon. The normal sign and magnitude of the Hall effect may be d
ue to the strongly ionic character of the bonding.