Heterostructure Solar Cells via Transfer Printing Technique

Anjali Thakran^1*, Chih Wei Chu²

¹Department of Physics, National Taiwan University, New Taipei, Taiwan
²Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan

* Presenter:Anjali Thakran, email:ANJALITHAKRAN83@GMAIL.COM

Perovskite tandem solar cells have been a popular choice due to their high efficiency and cost-effective photovoltaics, but their fabrication methods have been limited. In our work, we design a cascaded perovskite/perovskite heterostructure with a wide band gap and narrow bandgap and develop a facile fabrication route using transfer printing. The Br-rich (bottom) and Sn-rich (top) perovskite heterostructure device architecture maximizes incident photon utilization by reducing losses, including thermalization and spectral losses. The device exhibits a photovoltaic efficiency (PCE) of around 15%, with an electric field at the interfaces due to the higher LUMO position of the Br layer, which promotes faster charge carrier extraction. The stacked heterostructure is uniform, larger-area printed, and has an enlarged grain size. The reduced grain boundaries result in reducing defect states and suppressing recombination losses. The fabrication protocol allows for easy integration of other solution-based PV materials, making it a promising approach for stacked devices in optoelectronic or electronic devices.

Keywords: Mixed-halide perovskite, Transfer printing, Heterostructure