The Role of Nanoscale Seed Layers on the Enhanced Performance of Niobium doped TiO2 Thin Films on Glass.
Transparent conducting oxide (TCO) coatings with decreased cost and greater process or performance versatility are needed for a variety of optoelectronic applications. Among potential new TCO candidates, doped titanium dioxide is receiving particular interest. In this study, niobium-doped titania bilayer structures consisting of a nanoscale seed layer (deposited by atomic layer deposition or RF magnetron sputtering) followed by a thick bulk-like layer were grown directly on glass in order to examine the effects of the seed layer processing on the subsequent crystallization and electrical properties of these heterostructures. Observations from Raman spectroscopy suggest that higher oxygen content in the seed layer suppresses the formation of detrimental titania polymorph phases, found in films produced by annealing directly after synthesis without any exposure to oxygen. Furthermore, our results indicate that the generation of excellent Nb:TiO2 conductors on glass (without breaking vacuum) only occurs within a narrow processing range and that the sequential deposition of oxygen-poor layers on oxygen-rich layers is a critical step towards achieving films with low resistivity.
Department of Metallurgical and Materials Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, USA.
Stefan
S
Nikodemski
National Renewable Energy Laboratory, 15013 Denver W Pkwy, Golden, CO 80401, USA.
Arrelaine A
AA
Dameron
National Renewable Energy Laboratory, 15013 Denver W Pkwy, Golden, CO 80401, USA.
John D
JD
Perkins
Department of Metallurgical and Materials Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, USA.
Ryan P
RP
O'Hayre
National Renewable Energy Laboratory, 15013 Denver W Pkwy, Golden, CO 80401, USA.
David S
DS
Ginley
National Renewable Energy Laboratory, 15013 Denver W Pkwy, Golden, CO 80401, USA.
Joseph J
JJ
Berry