Highly conductive n- and p-type CuInO thin films by reactive evaporation

Undoped copper indium oxide films with conductivity three to four orders of magnitude higher than so far reported in this system, exhibiting both n- and p-type polarity are successfully prepared by reactive evaporation method. Hall coefficient and hot probe technique in conjunction with thermopower measurements ascertain the conductivity type of the films to be changing from n- to p-type, as the film composition assessed by energy dispersive analysis of X-rays changed from In rich to Cu rich. The conductivity is found to be similar to 2.1 x 10(1) S/cm in In-rich n-type films where as it is similar to 1.13 x 10(2) S/cm in Cu-rich p-type films with a corresponding increase in carrier concentration and carrier mobility in the latter. Scanning electron micrographs show close assembling of nanograins and X-ray diffraction reveals a change in orientation of crystallites from (006) to (600) as the composition goes from In rich to Cu rich. (C) 2014 Elsevier B.V. All rights reserved.