Oxygen and temperature effects on the electrochemical and electrochromic properties of rf-sputtered V2O5 thin films

Vanadium pentoxide (V2O5) thin films grown by rf-sputtering have been studied as a function of two growth parameters, O-2 content and substrate temperature, which influence importantly their structural, as well as their electrochemical and electrochromic properties. The increase in O-2 content appears to result in an increase of the grain size of the films, while the increase in substrate temperature leads in platelets perpendicular to the substrate, which enhance the porosity of the films. Films with low O-2 content (3%) and films grown at a substrate temperature of 300 degrees C, present enhanced charge storage properties of 553 mA h g(1) and large transmittance modulation ability. On the contrary, high O-2 content (11%) and a substrate temperature of 150 degrees C lead to improved coloration efficiency (at lambda = 400 nm), reaching values of 84.5 and similar to 132 cm(2)C (1), respectively. These findings are discussed in terms of structural and morphological changes occurring during the two parameters studied. (C) 2017 Elsevier Ltd. All rights reserved.