biostudies-literatureUnknown8(1)Saouma FOReducing the dimensionality of three-dimensional hybrid metal halide perovskites can improve their optoelectronic properties. Here, we show that the third-order optical nonlinearity, n <sub>2</sub>, of hybrid lead iodide perovskites is enhanced in the two-dimensional Ruddlesden-Popper series, (CH<sub>3</sub>(CH<sub>2</sub>)<sub>3</sub>NH<sub>3</sub>)<sub>2</sub>(CH<sub>3</sub>NH<sub>3</sub>) <sub>n-1</sub>Pb <sub>n</sub> I<sub>3n+1</sub> (n = 1-4), where the layer number (n) is engineered for bandgap tuning from E <sub>g</sub> = 1.60 eV (n = ∞; bulk) to 2.40 eV (n = 1). Despite the unfavorable relation, [Formula: see text], strong quantum confinement causes these two-dimensional perovskites to exhibit four times stronger third harmonic generation at mid-infrared when compared with the three-dimensional counterpart, (CH<sub>3</sub>NH<sub>3</sub>)PbI<sub>3</sub>. Surprisingly, however, the impact of dimensional reduction on two-photon absorption, which is the Kramers-Kronig conjugate of n <sub>2</sub>, is rather insignificant as demonstrated by broadband two-photon spectroscopy. The concomitant increase of bandgap and optical nonlinearity is truly remarkable in these novel perovskites, where the former increases the laser-induced damage threshold for high-power nonlinear optical applications.Hybrid metal halide perovskites can exhibit improved optoelectronic properties when their dimensionality is reduced. Here, Saouma et al. study the enhancement of third-order nonlinearities in two-dimensional lead iodide perovskites in the Ruddlesden-Popper series.Nature communications742https://www.ebi.ac.uk/biostudies/studies/S-EPMC5622136biostudies-literatureSelective enhancement of optical nonlinearity in two-dimensional organic-inorganic lead iodide perovskites.PMC5622136Saouma FOKanatzidis MGStoumpos CCWong JJang JIfalseSelective enhancement of optical nonlinearity in two-dimensional organic-inorganic lead iodide perovskites.Reducing the dimensionality of three-dimensional hybrid metal halide perovskites can improve their optoelectronic properties. Here, we show that the third-order optical nonlinearity, n <sub>2</sub>, of hybrid lead iodide perovskites is enhanced in the two-dimensional Ruddlesden-Popper series, (CH<sub>3</sub>(CH<sub>2</sub>)<sub>3</sub>NH<sub>3</sub>)<sub>2</sub>(CH<sub>3</sub>NH<sub>3</sub>) <sub>n-1</sub>Pb <sub>n</sub> I<sub>3n+1</sub> (n = 1-4), where the layer number (n) is engineered for bandgap tuning from E <sub>g</sub> = 1.60 eV (n = ∞; bulk) to 2.40 eV (n = 1). Despite the unfavorable relation, [Formula: see text], strong quantum confinement causes these two-dimensional perovskites to exhibit four times stronger third harmonic generation at mid-infrared when compared with the three-dimensional counterpart, (CH<sub>3</sub>NH<sub>3</sub>)PbI<sub>3</sub>. Surprisingly, however, the impact of dimensional reduction on two-photon absorption, which is the Kramers-Kronig conjugate of n <sub>2</sub>, is rather insignificant as demonstrated by broadband two-photon spectroscopy. The concomitant increase of bandgap and optical nonlinearity is truly remarkable in these novel perovskites, where the former increases the laser-induced damage threshold for high-power nonlinear optical applications.Hybrid metal halide perovskites can exhibit improved optoelectronic properties when their dimensionality is reduced. Here, Saouma et al. study the enhancement of third-order nonlinearities in two-dimensional lead iodide perovskites in the Ruddlesden-Popper series.2017-01-01T00:00:00Z2017 Sep2025-04-22T07:44:13.321Z2019-03-27T02:57:52ZS-EPMC56221362896344910.1038/s41467-017-00788-x