SPECIFIC / University of Swansea

A team from Swansea University used a new manufacturing method for flexible photovoltaics. The system is capable of spreading 4 layers of perovskite in a polymer film while maintaining high performance and low costs.

New performance record for printed perovskite-based solar cells. A group of scientists from the University of Swansea in Wales have successfully manufactured them with a roll-to-roll device that provides 12.2% conversion efficiency. This is the highest value ever reached for this specific type of photovoltaic energy.

The secret to success is the ability to combine the right printing technology with perovskite ink, while maintaining minimal material loss and ease of execution.

The only choice of active material for making printed solar cells might be perovskite, a class of synthetic oxides considered to be the most valuable substitutes for silicon.

Today, in fact, between the two semiconductors there is no longer any difference in efficiency. And although perovskite has not yet passed the scale-up phase, it can already expect reduced costs and production requirements. For example, despite silicon photovoltaics, these compounds do not need high temperatures or vacuum chambers for processing.

The possibility of processing them in solutions at low temperature offers the possibility of applying various printing and coating techniques, from screen printing to inkjet. In this specific case, researchers at Swansea University used a technology called “slot die linerThis solution allows even very viscous materials to be deposited on a substrate which passes under the nozzles, producing homogeneous and uniform films.

This method offers several advantages over its alternatives: the film thickness can be controlled before coating the substrate, and it can be extremely thin. It also offers a high efficiency in the use of the material, with minimal loss of semiconductors.

The solar cell prototype was made by covering the flexible plastic substrate with 4 layers of perovskite. The team added the top contact by thermal evaporation. However, scientists are working to make it possible to coat the slits for superior contact, so that a complete solar cell can only be produced with roll-to-roll printing.

Perovskite solar cells aim to increase efficiency and reduce costs of traditional photovoltaic production», Explains Rahul Patidar, principal investigator of the project. “They have the potential to be very efficient and relatively inexpensive to produce, so the goal is to improve manufacturing methods for scalability. This study indicates the next step towards commercialization“.

More information: pubs.rsc.org