Conductivity tuning of the ITO sol-gel materials by adjusting the tin oxide concentration, morphology and the crystalline size

摘要

A facile epoxide-driven method has been used to synthesize a series of highly electrically conductive mesoporous indium tin oxide (ITO) sol-gel nanomaterials with different morphologies and particle sizes. By altering the Sn content, the morphology and particle size of these materials undergo a drastic change. The effect of altering the morphology ultimately results in significant changes in the observed conductance of these materials. It became apparent that increasing the dopant concentration in the In2O3 matrix resulted in an increase in the average crystallite size present in the material. Additionally, altering Sn concentration modifies the morphology of the materials which at low concentration exhibit a spongelike microstructure that gradually changes to a to spherical-type architecture as the concentration of Sn increases. The coupling of the changing effect of particle size and morphology resulted in an observable difference in the materials conductivity. There was a general increase in conductivity observed which correlated with increasing Sn concentration with the maximum conductivity being observed for the sample with 17 wt% Sn. Increasing the Sn concentration above this point resulted in a decrease in the observed conductivity. This work provides a simple method to tune to the conductivity of ITO aerogels by simply altering the Sn concentration to modify the morphology and crystallite size of present within the materials. (C) 2016 Elsevier Inc. All rights reserved.