Surface activation of rigid and flexible substrates for thin film photovoltaics using atmospheric pressure plasma

Reducing fabrication costs is a major driving force in photovoltaic research. Atmospheric processes such as spin coating, spraying or printing are being developed to reduce the cost/Wp of CIGS, CZTS and perovskite solar technologies. For all technologies, surface cleaning and activation prior to thin film deposition is required and for this vacuum based low pressure plasma is a well-established technique. However, a vacuum based surface pre-treatment is not compatible with atmospheric deposition methods. We show that atmospheric-pressure plasmas are highly effective in activating the surface of substrates commonly used in photovoltaic device fabrication and demonstrate its effectiveness on both rigid and flexible substrates. The effectiveness of using atmospheric-pressure plasmas to increase surface energy is demonstrated using Water Contact Angle (WCA) measurements and chemical changes are analysed using X-ray Photoelectron Spectroscopy (XPS). Scanning Electron Microscopy (SEM) images show no alteration of the surface morphology of the substrates after the plasma treatment.