Tandem Perovskites on Silicon: Canadian technology from WattByWatt tested by CEA

The CEA and Canadian start-up WattByWatt are collaborating on the development of processes for manufacturing tandem perovskite-on-silicon photovoltaic cells and have achieved an initial promising result with an efficiency of 28%.

Founded in Montreal in 2020, WattByWatt is a young company specializing in perovskite materials and their implementation. It designs and manufactures single-junction perovskite mini-modules for indoor IoT and IIoT applications such as smoke detectors, locks, cameras, and remote controls.

In parallel, the company is developing innovative processes for depositing critical perovskite layers for both single-junction perovskite photovoltaic cells and so-called tandem perovskite-silicon solar cells. Its key innovation—exclusive to the company—lies in the ability to deposit the perovskite layer in ambient air using an industrializable wet-process technique. This method uses a proprietary ink formulation developed by WattByWatt.

The CEA, for its part, is recognized as a leading research player in tandem technology and regularly publishes world-class results in the field. Its laboratories, based at INES, have demonstrated the integration of WattByWatt’s ink and process for depositing the perovskite-based active layer within a CEA reference two-terminal tandem cell architecture. The resulting device achieved a power conversion efficiency of 28% on a 9 cm² surface.

These results open up new perspectives for the scaling and industrialization of tandem perovskite-on-silicon technology using high-potential processes.