TY  - JOUR
A1  - Steigert, Alexander
A1  - Kojda, Sandrino Danny
A1  - Ibaceta-Jaña, Josefa Fernanda
A1  - Abou-Ras, Daniel
A1  - Gunder, René
A1  - Alktash, Nivin
A1  - Habicht, Klaus
A1  - Wagner, Markus Raphael
A1  - Klenk, Reiner
A1  - Raoux, Simone
A1  - Szyszka, Bernd
A1  - Lauermann, Iver
A1  - Muydinov, Ruslan
T1  - Water-assisted crystallization of amorphous indium zinc oxide films
JF  - Materials today. Communications
N2  - Transparent conductive materials based on indium oxide remain yet irreplaceable in various optoelectronic applications. Amorphous oxides appear especially attractive for technology as they are isotropic, demonstrate relatively high electron mobility and can be processed at low temperatures. Among them is indium zinc oxide (IZO) with a large zinc content that is crucial for keeping the amorphous state but redundant for the doping. In this work we investigated water-free and water containing IZO films obtained by radio frequency sputtering. The correlation between temperature driven changes of the chemical state, the optical and electrical properties as well as the progression of crystallization was in focus. Such characterization methods as: scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, temperature dependent Hall-effect measurements and others were applied. Temperature dependent electrical properties of amorphous IZO and IZO:H2O films were found to evolve similarly. Based on our experience in In2O3:H2O (In2O3:H or IOH) we proposed an explanation for the changes observed. Water admixture was found to decrease crystallization temperature of IZO significantly from similar to 550 degrees C to similar to 280 degrees C. Herewith, the presence and concentration of water and/or hydroxyls was found to determine Zn distribution in the film. In particular, Zn enrichment was detected at the film's surface respective to the high water and/or hydroxyl amount. Raman spectra revealed a two-dimensional crystallization of w-ZnO which precedes regardless water presence an extensive In2O3 crystallization. An abrupt loss of electron mobility as a result of crystallization was attributed to the formation of ZnO interlayer on grain boundaries.
KW  - IZO
KW  - Thin films
KW  - TCOs
KW  - Crystallization
KW  - Water-assisted crystallization
Y1  - 2022
U6  - https://doi.org/10.1016/j.mtcomm.2022.103213
SN  - 2352-4928
VL  - 31
PB  - Elsevier
CY  - Amsterdam
ER  -