Synchrotron X-ray Studies of Novel Electronic MaterialsPublic Deposited
The promise of next-generation electronics, which combines features such as mechanical flexibility, optical transparency, and relatively low-cost, has stimulated tremendous research efforts during the past few years. As perhaps the most fundamental component of an electronic circuit, the design and optimization of the thin film transistor (TFT) is of great importance, especially the choice of the channel layer and dielectric layer materials. Transparent amorphous metal oxide (AMO) semiconducting materials replacing the traditional Si as the channel layer, and the invention of organic/inorganic hybrid ultra-thin dielectrics have demonstrated the ability to enhance performance and the potentials for the future device fabrication. However, despite the encouraging device performance, many fundamental aspects regarding their structures and non-electronic properties are largely unexplored. Herein, I will present how synchrotron X-ray characterization techniques can provide an improved view of these materials. I will show how long-period X-ray standing waves can measure the Br counteranion distributions within two self-assembled nano-dielectrics (SANDs) of differing polarity. Using synchrotron X-ray techniques and complementary DFT simulation, I will quantitatively determine the spacing, composition, elemental distribution, and molecular orientation within each trilayer-SAND heterolayer structure. Moreover, I will discuss the thermal stability study of AMOs synthesized by pulsed-laser deposition (PLD). The crystallization process of amorphous In2O3 films deposited as a function of deposition temperature under the isothermal-anneal condition is studied via in situ grazing incidence wide-angle X-ray scattering (GIWAXS) and level-set simulation. GIWAXS is also used to characterize the isochronal crystallization process of AMO thin films to systematically compare and study the effects of the secondary metal ions on the crystallization kinetics.