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

• DOI: 10.1016/j.matt.2023.05.028
• Publication Date: 2023-06-13T14:51:01Z
• Authors: 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
• Keywords: Photovoltaics; Surface passivation; Halide perovskite; 548; Interface science; [CHIM.MATE]Chemical Sciences/Material chemistry; [SPI.MAT]Engineering Sciences [physics]/Materials

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 cm−2) compared with control perovskite solar cells, resulting in bifacial perovskite/silicon tandem solar cells with power generation densities >27 mW cm−2. ; This work was supported by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under award nos. OSR-CARF/CCF-3079, OSR-CRG2019-4093, OSR-CRG2020-4350, IED OSR-2019-4208, IED OSR-2019-4580, and REI/1/4833-01-01. E.U. thanks Alessandro Genovese from KAUST Imaging and Characterization Core Lab for the TEM images. S.T., B.C., and E.H.S. thank the CLS for its support. GIWAXS patterns were collected at the BXDS Beamline at the CLS with the assistance of Dr. Adam Leontowich and Dr. Chang-Yong Kim. The CLS is funded by NSERC, the Canadian Institutes of Health Research, the Canada Foundation for Innovation, the government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. This research was made possible by the US Department of the Navy, Office of Naval Research Grant (N00014-20-1-2572). P.S. thanks the French Agence Nationale de la Recherche for funding under the contract ...