Luminescent lead bromide hybrid perovskites

Depuis 8 ans, les pérovskites hybrides (PHs) organique –inorganique sont apparues comme des semi-conducteurs prometteurs pour des applications photovoltaïques et diodes électroluminescentes (PeLEDs). C’est dans ce contexte que se situent les résultats de cette thèse.1/Un premier objectif était la synthèse des PHs ayant une émission à bande large (lumière blanche), et à rendements de photoluminescence (PLQE) élevés. Une première série de PHs 1D de réseau inorganique PbnBr4n+2 (n=1, 2, 3, 4), et des pérovskites hybrides 2D sont obtenus, les PLQE étant de 28% et 14%, respectivement.2/ La deuxième partie de la thèse est dédié à l’étude structural et des propriétés de luminescence d’une famille de pérovskites 3D originale, déficientes en plomb et en brome (d-PHs). Alors que la pérovskite 3D APbBr3 n’est pas émissive à température ambiante à l’état de bulk, nous montrons que ces d-PHs le sont, les rendant prometteurs pour des applications PeLEDs.3/ La troisième partie est l’étude de la pérovskite hybride 2D , (HEA)2(FA)2Pb2Br8 qui présente une émission étroite dans le vert et un effet de luminescence mécanochromique (MCL) réversible. Des PeLEDs ont également été préparées, ce qui est sans précédent pour une telle pérovskite 2D.4/La quatrième partie est consacré à l’étude d’un composite constitué d’un mélange de pérovskite 3D MAPbBr3 et de pérovskite 2D (CO2H(CH2)n-1NH3)2Pbr4 (n= 4, 6). Nous montrons que la composite présente des propriétés d’émission différentes de ceux de ses deux constituants. D’autre part, un phénomène MCL (réversible) spectaculaire est observé, ce qui met en évidence le rôle essentiel de l’interface dans des processus de transfert d’énergie.Since 8 years, organic-inorganic hybridperovskites (HPs) have emerged as promising semiconductors for photovoltaic applications and light-emitting diodes (PeLEDs). It is in this context that the results of this thesis lie.1 / A first objective was the synthesis of HPs havinga broadband emission (white light), and high photoluminescence yields (PLQE). A first series of1D PHs of inorganic network PbnBr4n + 2 (n = 1, 2, 3,4), and 2D hybrid perovskites are obtained, the PLQE being 28% and 14%, respectively.2 / The second part of the thesis is dedicated to the structural study and luminescence properties of a family of original 3D perovskites, deficient in leadand bromine (d-HPs). While perovskite 3D APbBr3is not emissive at room temperature in the bulk state,we show that these d-HPs are, making them promising for PeLEDs applications.MAPbBr3 and 2D perovskite (CO2H (CH2) n-1NH3)2Pbr4 (n = 4, 6). We show that the composite hase mission properties different from those of its two constituents. On the other hand, a spectacular (reversible) MCL phenomenon is observed, which highlights the essential role of the interface in energy transfer processes.3 / The third part is the study of the hybrid perovskite2D , (HEA) 2 (FA) 2Pb2Br8 which has a narrow emission in green and a reversible mechanochromic luminescence (MCL) effect. PeLEDs have also been prepared, which is unprecedented for such 2Dperovskite.4 / The fourth part is devoted to the study of a composite consisting of a mixture of perovskite 3DMAPbBr3 and 2D perovskite (CO2H (CH2) n-1NH3)2Pbr4 (n = 4, 6). We show that the composite has emission properties different from those of its two constituents. On the other hand, a spectacular (reversible) MCL phenomenon is observed, which highlights the essential role of the interface in energy transfer processes

Pérovskites hybrides bromoplombate luminescentes

Since 8 years, organic-inorganic hybridperovskites (HPs) have emerged as promising semiconductors for photovoltaic applications and light-emitting diodes (PeLEDs). It is in this context that the results of this thesis lie.1 / A first objective was the synthesis of HPs havinga broadband emission (white light), and high photoluminescence yields (PLQE). A first series of1D PHs of inorganic network PbnBr4n + 2 (n = 1, 2, 3,4), and 2D hybrid perovskites are obtained, the PLQE being 28% and 14%, respectively.2 / The second part of the thesis is dedicated to the structural study and luminescence properties of a family of original 3D perovskites, deficient in leadand bromine (d-HPs). While perovskite 3D APbBr3is not emissive at room temperature in the bulk state,we show that these d-HPs are, making them promising for PeLEDs applications.MAPbBr3 and 2D perovskite (CO2H (CH2) n-1NH3)2Pbr4 (n = 4, 6). We show that the composite hase mission properties different from those of its two constituents. On the other hand, a spectacular (reversible) MCL phenomenon is observed, which highlights the essential role of the interface in energy transfer processes.3 / The third part is the study of the hybrid perovskite2D , (HEA) 2 (FA) 2Pb2Br8 which has a narrow emission in green and a reversible mechanochromic luminescence (MCL) effect. PeLEDs have also been prepared, which is unprecedented for such 2Dperovskite.4 / The fourth part is devoted to the study of a composite consisting of a mixture of perovskite 3DMAPbBr3 and 2D perovskite (CO2H (CH2) n-1NH3)2Pbr4 (n = 4, 6). We show that the composite has emission properties different from those of its two constituents. On the other hand, a spectacular (reversible) MCL phenomenon is observed, which highlights the essential role of the interface in energy transfer processes.Depuis 8 ans, les pérovskites hybrides (PHs) organique –inorganique sont apparues comme des semi-conducteurs prometteurs pour des applications photovoltaïques et diodes électroluminescentes (PeLEDs). C’est dans ce contexte que se situent les résultats de cette thèse.1/Un premier objectif était la synthèse des PHs ayant une émission à bande large (lumière blanche), et à rendements de photoluminescence (PLQE) élevés. Une première série de PHs 1D de réseau inorganique PbnBr4n+2 (n=1, 2, 3, 4), et des pérovskites hybrides 2D sont obtenus, les PLQE étant de 28% et 14%, respectivement.2/ La deuxième partie de la thèse est dédié à l’étude structural et des propriétés de luminescence d’une famille de pérovskites 3D originale, déficientes en plomb et en brome (d-PHs). Alors que la pérovskite 3D APbBr3 n’est pas émissive à température ambiante à l’état de bulk, nous montrons que ces d-PHs le sont, les rendant prometteurs pour des applications PeLEDs.3/ La troisième partie est l’étude de la pérovskite hybride 2D , (HEA)2(FA)2Pb2Br8 qui présente une émission étroite dans le vert et un effet de luminescence mécanochromique (MCL) réversible. Des PeLEDs ont également été préparées, ce qui est sans précédent pour une telle pérovskite 2D.4/La quatrième partie est consacré à l’étude d’un composite constitué d’un mélange de pérovskite 3D MAPbBr3 et de pérovskite 2D (CO2H(CH2)n-1NH3)2Pbr4 (n= 4, 6). Nous montrons que la composite présente des propriétés d’émission différentes de ceux de ses deux constituants. D’autre part, un phénomène MCL (réversible) spectaculaire est observé, ce qui met en évidence le rôle essentiel de l’interface dans des processus de transfert d’énergie

Synthesis and Characterization of (FA)₃(HEA)₂Pb₃I₁₁: A Rare Example of <1 1 0>-Oriented Multilayered Halide Perovskites

For DFT calculations, this work was granted access to the HPC resources of TGCC/CINES/IDRIS under the allocation 2020-A0090907682 made by GENCIInternational audienceMetal-halide perovskites have recently demonstrated great potential for a wide variety of optoelectronic applications, with their layered subfamily offering improved stability as compared to their 3D analogs. Among the layered compounds, subclass of terminated compounds are currently dominating the field, while subclass is comparably much less explored. Here we report on the synthesis of (FA) 3 (HEA) 2 Pb 3 I 11 obtained by room-temperature liquid-gas diffusion involving the intermediate-size cation hydroxyethylammonium (HEA +), formamidinium (FA +) and PbI 2 dissolved in an acidic solution. This multilayered hybrid perovskite is a rare example of a m= 3 member of the -oriented series (A') 2 (A) m B m X 3m+2. Structural characterization based on X-ray diffraction and NMR investigations reveals that the small size cation FA + is located both in the inner layer of the perovskite sheet, but also in the interlayer space, while the intermediate-size cation HEA + is situated in the outer cavities of the perovskite sheet. (FA) 3 (HEA) 2 Pb 3 I 11 exhibits a broad absorption band in the visible region (400-650 nm) leading to an optical band gap of 1.96 eV. Electronic structure calculations confirm the direct nature of the band gap and evidence sizeable inter layer electronic coupling related to short I…I distances. These features are reminiscent of those observed for -oriented Pb 3 I 10 analogs that have shown photovoltaic efficiencies over 18%. These findings should prompt further investigations for the design of other -oriented multilayered (m= 3, 4,…) metal halide perovskites

Quasi 3D electronic structures of Dion-Jacobson layered perovskites with exceptional short interlayer distances.

International audienceIn the field of perovskite solar cells (PSCs), 3D/2D heterostructures are a promising route to obtain highly efficient and stable devices. Herein, inspired by dications which have afforded rare layered perovskites called Dion-Jacobson (DJ), with short interlayer distances, we designed and synthesized the new 2-iodopropane-1,3-diamonium dication (DicI), and we successfully obtained multi-n 2D layered perovskites (DicI)(MA)n- 1PbnI3n+1 (n= 1-4, MA+= methylammonium). As a result of a suitable size of the dication which well fits, in projection to the layer planes, in the square defined by four adjacent apical iodides, as well as halogen bonding between organic iodine and apical iodides (I(ap)) of perovskite layers, a perfect eclipsed configuration between adjacent layers takes place, yielding unprecedented short I(ap)….I(ap) distances, as small as 3.882 Å in (DicI)(MA)2Pb3I10. Density Functional Theory (DFT) calculations highlight unusually strong valence band dispersion along the the →Z direction. Effective masses for out-of-plane motions of holes are estimated on par with values computed for 3D perovskites, and similar to in-plane effective masses in 2D multilayered perovskites. This indicates these layered compounds feature quasi 3D electronic structures, hence appearing as promising candidates for PSCs heterostructure