Zhou T, Shao B. Atomically thin two-dimensional hybrid perovskites using hydrophobic superalkali cations with tunable electron transition type.
Phys Chem Chem Phys 2023;
25:27409-27416. [PMID:
37794817 DOI:
10.1039/d3cp03721e]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
The direct band gaps of two-dimensional (2D) metal halide perovskites can be tuned via component engineering, but their electron transition type hardly changes. Herein, atomically thin (C5NH6)2MX4 (M = Ge, Sn, Pb; X = Cl, Br, I) hybrid perovskites with hydrophobic superalkali cations were systematically explored using high-throughput hybrid density functional calculations and ab initio molecular dynamics simulations. We found that the electron transition between the M and X atoms was converted into that between the C5NH6 parts and X atoms via X change in the 2D (C5NH6)2MX4 perovskites. Negative formation energy, stable thermodynamic and kinetic properties, sharp valence bands, and tunable direct band gaps were obtained for the 2D perovskites. A power conversion efficiency (PCE) of 32.54% was obtained in theory for the passivated cubic NH2CHNH2PbI3 (FAPbI3) perovskite containing the 2D (C5NH6)2PbI4 perovskite. The hybrid Pb-free (C5NH6)2SnI4 perovskite with a direct bandgap of 1.56 eV may be viewed as a potential passivation material for perovskite devices. Moreover, the C5NH6 cations and X atoms show different hydrogen bonding interactions, which can be extended to other atomically thin organic-inorganic hybrid perovskites.
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