Perovskite-based organic-inorganic materials with varying dimensions (from 3D to 2D, 1D, and 0D) have emerged as a new material platform with applications as thin-film solar cells or light-emitting diodes. These materials combine organic molecular cations with inorganic (BX6) anionic octahedra (where B is usually Pb, Sn, or another metal; and X, a halide), which form corner-, edge-, or face-sharing crystalline structures. The electronic and vibrational couplings between the inorganic and organic moieties are expected to result in hybrid excitonic states with intriguing properties. Also, the nature of the perovskites surfaces and their interfaces with metal-oxide electrodes and organic hole- and electron-transport materials, is of interest.
Our current computational studies on perovskite materials focus on:
2D hybrid perovskites
(i) Understanding the ground and excited-state electronic properties of 2D hybrid perovskite systems with organic functional molecular spacers interacting with inorganic perovskite layers of various thicknesses.
(ii) Understanding the defect physics, chemistry, and dynamics in bulk perovskites and at their interfaces with technology-relevant metal oxides in perovskite-based light-emitting diodes or solar cells.
2D/3D mixed perovskites
(iii) Investigating the geometric and electronic structures of 2D/3D mixed perovskites, which have been developed lately to improve both the stability and performance of perovskite-based solar cells.
S. Silver, S.N. Xun, H. Li, J.L. Brédas, and A. Kahn, “Structural and Electronic Impact of an Asymmetric Organic Ligand in Diammonium Lead Iodide Perovskites”, Advanced Energy Materials, 10, 1903900 (2020).
S.F. Zhang, X.K. Chen, A.M. Ren, H. Li, and J.L. Brédas, “Impact of Organic Spacers on the Carrier Dynamics in 2D Hybrid Lead-Halide Perovskites”, ACS Energy Letters, 4, 17-25 (2019).
J. Yin, P. Maity, R. Naphade, B. Cheng, J-H. He, O.M. Bakr, J.L. Brédas, O.F. Mohammed, “Tuning Hot Carrier Cooling Dynamics by Dielectric Confinement in Two-Dimensional Hybrid Perovskite Crystals”, ACS Nano, 13, 12621-12629 (2019).
S. Silver, Q. Dai, H. Li, J.L. Brédas, and A. Kahn, “Quantum Well Energetics of a n=2 Ruddlesden-Popper Phase Perovskite”, Advanced Energy Materials, 9, 1901005 (2019).
J. Yin, G. Ahmed, O. Bakr, J.L. Brédas, and O. Mohammed, "Unlocking the Effect of Trivalent Metal Doping in All-Inorganic CsPbBr3 Perovskite", ACS Energy Letters, 4, 789-795 (2019).
J. Yin, P. Maity, L.Xu, A. El-Zohry, H. Li, O. Bakr, J.L. Brédas, and O. Mohammed, “Layer-Dependent Rashba Band Splitting in 2D Hybrid Perovskites”, Chemistry of Materials, 30, 8538-8545 (2018).
S. Silver, J. Yin, H. Li, J.L. Brédas, and A. Kahn, “Characterization of the Valence and Conduction Band Levels of n=1 Two-Dimensional Perovskites: A Combined Experimental and Theoretical Investigation”, Advanced Energy Materials, 8, 1703468 (2018).
Jun Yin, Partha Maity, Michele De Bastiani, Ibrahim Dursun, Osman M Bakr, Jean-Luc Brédas, and Omar F Mohammed, “Molecular Behavior of Zero-dimensional Perovskites”, Science Advances, 3, e1701793 (2017).
Jun Yin, Hong Li, Daniele Cortecchia, Cesare Soci, and Jean-Luc Bredas, “Excitonic and Polaronic Properties of 2D Hybrid Organic–Inorganic Perovskites”, ACS Energy Letters, 2, 417 (2017).