Effects of O7+ swift heavy ion irradiation on indium oxide thin films

Indium oxide thin films deposited by spray pyrolysis were irradiated by 100 MeV O7+ ions with different fluences of 5 x 10(11),1 x 10(12) and 1 x 10(13) ions/cm(2). X-ray diffraction analysis confirmed the structure of indium oxide with cubic bixbyite. The strongest (2 2 2) orientation observed from the as-deposited films was shifted to (4 0 0) after irradiation. Furthermore, the intensity of the (4 0 0) orientation was decreased with increasing fluence together with an increase in (2 2 2) intensity. Films irradiated with maximum fluence exhibited an amorphous component. The mobility of the as-deposited indium oxide films was decreased from similar to 78.9 to 43.0 cm(2)/V s, following irradiation. Films irradiated with a fluence of 5 x 10(11) ions/cm2 showed a better combination of electrical properties, with a resistivity of 4.57 x 10(-3) Omega cm, carrier concentration of 2.2 x 10(19) cm(-3) and mobility of 61.0 cm(2)/V s. The average transmittance obtained from the as-deposited films decreased from similar to 81% to 72%, when irradiated with a fluence of 5 x 10(11) ions/cm(2). The surface microstructures confirmed that the irregularly shaped grains seen on the surface of the as-deposited films is modified as "radish-like" morphology when irradiated with a fluence of 5 x 10(11) ions/cm(2). (C) 2011 Elsevier B.V. All rights reserved.