Importance of Local Bond Order to Conduction in Amorphous, Transparent, Conducting Oxides: The Case of Amorphous ZnSnOy

Ainur Zhussupbekova; Aitkazy Kaisha; Rajani K Vijayaraghavan; Karsten Fleischer; Igor V Shvets; David Caffrey

doi:10.1021/acsami.9b06210

Importance of Local Bond Order to Conduction in Amorphous, Transparent, Conducting Oxides: The Case of Amorphous ZnSnO_y

ACS Appl Mater Interfaces. 2019 Nov 27;11(47):44399-44405. doi: 10.1021/acsami.9b06210. Epub 2019 Nov 12.

Authors

Ainur Zhussupbekova¹, Aitkazy Kaisha¹, Rajani K Vijayaraghavan², Karsten Fleischer^{1

3}, Igor V Shvets¹, David Caffrey¹

Affiliations

¹ School of Physics and Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) , Trinity College Dublin , Dublin 2 , Ireland.
² School of Electronic Engineering , Dublin City University , Glasnevin, Dublin 9 , Ireland.
³ School of Physics , Dublin City University , Dublin 9 , Ireland.

PMID: 31638369
DOI: 10.1021/acsami.9b06210

Abstract

In this report, reactive and nonreactive sputtering of amorphous ZnSnO_y (a-ZnSnO_y) was investigated, and extensive composition maps have been measured by X-ray photoelectron spectroscopy. The comprehensive analysis of the ((ZnO)_x(SnO₂)_1-x) composition reveals that the best Zn/Sn ratio for high conductivity of the material can vary depending on the deposition technique utilized. Best conductivities of 225 S/cm were found to occur at x = 0.32 for reactive sputtering of a Sn target and x = 0.27 for nonreactive sputtering of a SnO₂ target. These values correspond to unstable polymorphs of a-ZnSnO_y, ZnSn₂O₅, and ZnSn₃O₇. Distinct local bonding arrangements have been confirmed by Raman spectroscopy.

Keywords: Raman spectroscopy; X-ray photoelectron spectroscopy; amorphous oxide semiconductor; magnetron sputtering; transparent conducting oxide; zinc tin oxide.