Roll to roll atmospheric pressure plasma enhanced CVD of titania as a step towards the realisation of large area perovskite solar cell technology

Atmospheric pressure plasma enhanced CVD (AP PECVD) systems have attracted considerable interest in recent years due to the significant benefits for large area, low cost substrates and low temperature operation. In this work we describe the use of a bespoke roll to roll AP PECVD process to produce large area, functional TiO_2-x films for use as hole blocking electron transport layers in perovskite solar cell architectures, a critical component typically produced by spin coating or vacuum based technologies. The AP PECVD produced films can be used to construct cells with overall efficiencies greater than from the sputtered reference material (13.57 vs. 13.15% maximum power point for 1 cm² cells). Discussion of the cell properties suggests scope for further optimisation, maximising the potential of this approach.