Scaling up production of perovskite solar cells
Perovskite solar cells are relatively easy to produce in the lab in small batches. The challenge has been to scale up production so that they are useful for real-world applications.
Spin coating is one way of fabricating thin-film solar cells in the lab. It is a method of depositing uniform thin films to flat substrates.
Coating material is applied to the centre of a substrate, which is then rotated at high speed so that the centrifugal force causes the coating material to spread and dry. This results in a substrate covered with a thin, homogeneous film.
Spin coating is not suitable for industrial-scale fabrication.
Modifying the fabrication process
We developed a small-scale slot-die coater to fabricate perovskite cells in the lab using a deposition process that is transferable to industry.
Slot die coating, a non-contact deposition technique, delivers a precise volume of material to a substrate while the coating die is moved in a controlled manner in relation to the substrate. This method is directly transferable to industrial roll-to-roll production.
However, coating and printing of electroactive layers can result in thin films with defects — cracks and pinholes — which lower the efficiency of large-area solar cells. To combat this, our researchers developed an effective polymer-based additive to reduce the amount of cracks and pinholes in the electroactive layers of perovskite solar cells.
CSIRO has patented this additive technology.
A new technique for the lab and industrial applications
Since the purpose-built lab-scale slot-die coater was installed, the pace of research has increased, and the transition from the lab to potential industry use has been streamlined.
Using a polymer-based additive to create pinhole and crack-free films is an invaluable contribution to solar photovoltaic research. The method also overcomes a major barrier to producing high-performance, large-area perovskite solar cells.