Structural and Optoelectronic Properties of 2D Multilayered Perovskites

2D multilayered perovskites share similarities with 3D perovskites including direct electronic band gaps, strong spin-orbit coupling, sizeable optical absorptions, small effective masses, Rashba-like effects [1]. Interestingly, they exhibit other attractive features related to tunable quantum and dielectric confinements, strong lattice anisotropy, more complex combinations of atomic orbitals and lattice dynamics, extensive chemical engineering possibilities. This will be illustrated by recent combined experimental and theoretical studies on excitons, formation of edge states, hot carrier effects and carrier localization [3-6]. More, combined in 2D/3D bilayer structures using new versatile growth methods, excellent solar cell device stability can be achieved [7]. Band alignment calculations nicely explain the difference of performances for ni-p or p-i-n devices [8]. The lattice mismatch concept can provide guidance for the choice of the proper 2D/3D combination [1,2].<br/><br/>[1] J.-C. Blancon et al, Semiconductor physics of organic-inorganic 2D halide perovskites, Nature Nano.15 969 (2020)<br/>[2] M. Kepenekian et al, Concept of lattice mismatch and emergence of surface states in two-dimensional hybrid perovskite quantum wells, Nanoletters (2018)<br/>[3] Y. Qin et al, Dangling octahedra enable edge states in 2D lead halide perovskites, Adv. Mat. 34, 2201666 (2022)<br/>[4] W. Li et al, Light-activated interlayer contraction in two-dimensional perovskites for high-efficiency solar cells, Nature Nano, 17, 45 (2022)<br/>[5] S. Cuthriell et al, Nonequilibrium Lattice Dynamics in Photoexcited 2D Perovskites, Adv. Mat. 34, 2202709 (2022)<br/>[6] H. Zhang et al, Ultrafast relaxation of lattice distortion in two-dimensional perovskites, Nature Physics 19, 545 (2023)<br/>[7] S. Sidhik et al, Deterministic fabrication of 3D/2D perovskite bilayer stacks for durable and efficient solar cells, Science 377, 1425 (2022)<br/>[8] B. Traore et al, A theoretical framework for microscopic surface and interface dipoles, work functions and valence band alignments in 2D and 3D halide perovskite heterostructures, ACS Energy Letters, 7, 349 (2022)<br/><br/><br/>Acknowledgments: The work at institute FOTON and Institut des Sciences Chiiques de Rennes was supported by the European Union’s Horizon 2020 research and innovation program under grant agreement 861985 (PeroCUBE). M.Z. acknowledges funding from the European Union’s Horizon<br/>2020 research and innovation programme under the Marie Sklodowska-Curie grant<br/>agreement No. 899546. J.E. is supported by Institut Universitaire de France.