X-ray absorption spectroscopy elucidates the impact of structural disorder on electron mobility in amorphous zinc-tin-oxide thin films

We investigate the correlation between the atomic structures of amorphous zinc-tin-oxide (a-ZTO) thin films grown by atomic layer deposition (ALD) and their electronic transport properties. We perform synchrotron-based X-ray absorption spectroscopy at the K-edges of Zn and Sn with varying [Zn]/[Sn]...

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Bibliographic Details
Main Authors: Siah, Sin Cheng, Lee, Sang Woon, Lee, Yun Seog, Heo, Jaeyeong, Shibata, Tomohiro, Segre, Carlo U., Gordon, Roy G., Buonassisi, Tonio
Other Authors: Massachusetts Institute of Technology. Department of Mechanical Engineering
Format: Article
Language:en_US
Published: American Institute of Physics (AIP) 2015
Online Access:http://hdl.handle.net/1721.1/97238
https://orcid.org/0000-0001-8345-4937
Description
Summary:We investigate the correlation between the atomic structures of amorphous zinc-tin-oxide (a-ZTO) thin films grown by atomic layer deposition (ALD) and their electronic transport properties. We perform synchrotron-based X-ray absorption spectroscopy at the K-edges of Zn and Sn with varying [Zn]/[Sn] compositions in a-ZTO thin films. In extended X-ray absorption fine structure (EXAFS) measurements, signal attenuation from higher-order shells confirms the amorphous structure of a-ZTO thin films. Both quantitative EXAFS modeling and X-ray absorption near edge spectroscopy (XANES) reveal that structural disorder around Zn atoms increases with increasing [Sn]. Field- and Hall-effect mobilities are observed to decrease with increasing structural disorder around Zn atoms, suggesting that the degradation in electron mobility may be correlated with structural changes.