Advancements in Transparent Conducting Oxides: Amorphous IO & ZITO

In this research project, we set out to discover why the compounds indium oxide (IO) and zinc-indium-tin-oxide (ZITO) are better semiconductors in their amorphous state, just before they become crystalline. A series of IO and ZITO thin films ranging from fully amorphous to fully crystalline were prepared. We analyzed their x-ray pair distribution function data collected at Argonne National Laboratory. We evaluated the films’ lateral and depth uniformity by analyzing different sections of the data that were measured at different penetration depths. A variety of software packages were used, including GSAS II, PDFgetX3, and MATLAB. For both IO and ZITO, we found that the in-plane and out-of-plane atomic structures differed suggesting that the films are not laterally homogeneous. Shorter bond lengths correlated with high electron mobility. These results will be compared with molecular dynamic simulations to better understand which local atomic structure produces enhanced electrical properties.