Enhanced optical performance of APCVD zinc oxide via post growth plasma treatment at atmospheric pressure

Hodgkinson, JL; Yates, HM; Sheel, DW

Abstract

The use of atmospheric pressure (AP) CVD to produce
highly developed Transparent Conducting oxides (TCO)
for thin film photovoltaic systems has significant potential
to reduce manufacturing costs and increase the product
scope via in-line processing compared to off-line, low
pressure techniques. A further advantage of APCVD is
the ability control surface morphology via growth parameters, a key factor in controlling the distribution of
scattered light at the TCO/absorber interface. The nanoscale
features may be further optimised via post growth etching, for example, to round sharp vertices or induce or
exaggerate texture in a film material that is intrinsically
smooth. This is normally achieved via low pressure
plasma treatments or wet chemical processes, hence the
presented novel AP plasma approach here offers reduced
capital costs combined with ease of scalability and process
integration. In this work we describe the multi-scale
manipulation of an APCVD grown ZnO via surface morphological
modification, achieved by the application of
an atmospheric pressure plasma etch system. The modified
surfaces are evaluated for optical and morphological
properties. Initial research has shown that under the correct plasma etch conditions, optical haze can be increased by as much as 20%, with the crucial additional ability to also tailor the film surface features. The use of audio frequency and sub-microsecond pulsed plasmas for etching are compared in terms of activity and control.

Citation

Hodgkinson, J., Yates, H., & Sheel, D. (2015). Enhanced optical performance of APCVD zinc oxide via post growth plasma treatment at atmospheric pressure. physica status solidi (c), 12(7), 1016-1021. https://doi.org/10.1002/pssc.201510011

• Journal Article Type: Article
• Acceptance Date: May 18, 2015
• Online Publication Date: Jun 5, 2015
• Publication Date: Jun 5, 2015
• Deposit Date: Jun 29, 2015
• Journal: Physica Status Solidi (c)
• Print ISSN: 1862-6351
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 7
• Pages: 1016-1021
• DOI: https://doi.org/10.1002/pssc.201510011
• Publisher URL: http://dx.doi.org/10.1002/pssc.201510011
• Related Public URLs: http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1610-1642a
• Additional Information: Projects : Process Line Implementation for Applied Surface Nanotechnologies (PLIANT)