Front-contact passivation through 2D/3D perovskite heterojunctions enables efficient bifacial perovskite/silicon tandem solar cells

by Esma Ugur, Erkan Aydin, Michele De Bastiani, George T. Harrison, Bumin K.  Yildirim, Sam Teale, Bin Chen, Jiang Liu, Mingcong Wang, Akmaral Seitkhan, Maxime Babics, Anand S. Subbiah, Ahmed Ali Said, Randi Azmi, Atteq ur Rehman, Thomas G Allen, Philip Schulz, Edward H. Sargent, Frédéric Laquai, Stefaan De Wolf
Article Year: 2023 DOI:


Ugur, E., Aydin, E., De Bastiani, M., T. Harrison, G., K. Yildirim, B., Teale, S., Chen, B., Liu, J., Wang, M., Seitkhan, A., Babics, M., S. Subbiah, A., Ali Said, A., Azmi, R., Ur Rehman, A., G. Allen, T., Schulz, P., H. Sargent, E., Laquai, F., De Wolf, S.


Surface passivation by thin-slab 2D perovskites is an effective method to suppress interfacial carrier recombination of 3D metal halide perovskite photoabsorbers. However, improving device performance by integrating such 2D/3D perovskite heterojunctions in the sunward, transparent contacts of perovskite solar cells is not evident due to the high exciton binding energies of phase-pure 2D perovskites, which may result in inefficient free-carrier generation and collection. Here, we overcome this challenge by tuning the dimensionality of 2D perovskites via structural isomers of butylammonium (BA) as a small organic cation, occupying the A-site of the 2D perovskite lattice. The discontinuous iso-BA-based 2D crystals on the 3D perovskite surface yield improved interfacial passivation and enhanced hole extraction. Besides an increased open circuit voltage, this remarkably leads to an enhanced photocurrent (1 mA cm2 ) compared with control perovskite solar cells, resulting in bifacial perovskite/silicon tandem solar cells with power generation densities >27 mW cm2 .


bifacial tandem solar cells Perovskite/silicon tandem solar cells 2D/3D perovskite heterojunction