81Br NQR and 119Sn Mössbauer Study for MSnBr3 (M=Cs and CH3NH3)

Yamada, Koji; Nose, S.; Umehara, Takako; Okuda, Takuo; Ichiba, Sumio

doi:10.1246/bcsj.61.4265

Cited by 45 publications

(31 citation statements)

References 15 publications

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“…Experimentally, we observe that the 119 Sn resonances become narrower as the temperature increases (Figure 7a and Table S1), which shows that T 2 increases with temperature. Since determining the relaxation regime for the quadrupolar partner is not straightforward in this case due to its very large quadrupole coupling constant, 110 we employ the determined activation energy as a constraint to identify the relevant relaxation mechanism. Plotting ln( 119 Sn T 1 /s) as a function of the inverse temperature yields an Arrhenius plot ( Figure 7b) from which we determine the activation energy of the process driving the relaxation (Table 1 and Table S2).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Local Structure and Dynamics in Methylammonium, Formamidinium, and Cesium Tin(II) Mixed-Halide Perovskites from ¹¹⁹Sn Solid-State NMR

et al. 2020

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Organic−inorganic tin(II) halide perovskites have emerged as promising alternatives to lead halide perovskites in optoelectronic applications. While they suffer from considerably poorer performance and stability in comparison to their lead analogues, their performance improvements have so far largely been driven by trial and error efforts due to a critical lack of methods to probe their atomic-level microstructure. Here, we identify the challenges and devise a 119 Sn solid-state NMR protocol for the determination of the local structure of mixed-cation and mixed-halide tin(II) halide perovskites as well as their degradation products and related phases. We establish that the longitudinal relaxation of 119 Sn can span 6 orders of magnitude in this class of compounds, which makes judicious choice of experimental NMR parameters essential for the reliable detection of various phases. We show that Cl/Br and I/Br mixed-halide perovskites form solid alloys in any ratio, while only limited mixing is possible for I/Cl compositions. We elucidate the degradation pathways of Cs-, MA-, and FA-based tin(II) halides and show that degradation leads to highly disordered, qualitatively similar products, regardless of the A-site cation and halide. We detect the presence of metallic tin among the degradation products, which we suggest could contribute to the previously reported high conductivities in tin(II) halide perovskites. 119 Sn NMR chemical shifts are a sensitive probe of the halide coordination environment as well as of the A-site cation composition. Finally, we use variable-temperature multifield relaxation measurements to quantify ion dynamics in MASnBr 3 and establish activation energies for motion and show that this motion leads to spontaneous halide homogenization at room temperature whenever two different pure-halide perovskites are put in physical contact.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Local Structure and Dynamics in Methylammonium, Formamidinium, and Cesium Tin(II) Mixed-Halide Perovskites from ¹¹⁹Sn Solid-State NMR

et al. 2020

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“…'Single line in the 8 1~r nqr spectrum (142). /There are further displacive transitions on cooling (121-123), but they are not of interest in the present context.…”

Section: Active Lp E= Inactive L P Conversionmentioning

confidence: 93%

The lone electron pair and crystal packing: observations on pyramidal YEL₃^ε species, abinitio calculations, and the crystal structures of Me₃SOI, Et₃SI, (Me₃S)₂SnCl₆, (Me₃SO)₂SnCl₆, and (Et₃S)₂SnCl₆

Knop¹,

Linden²,

Vincent³

et al. 1989

Can. J. Chem.

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The results of a detailed analysis of typical situations in crystals containing trigonal-pyramidal YEL3' species are used to argue that, per se, the lone electron pair (E, LP) on the Y atom determines neither the crystal structure nor the onentation of the Y EL3' units in the crystal. Considered as a space-filling entity, the LP has practically no effective volume of its own. Whatever space-filling or orienting properties may be associated with the presence of the LP, they are not autonomous; they arise from the intrinsic stereochemical involvement of the LP in the geometry of and the charge distribution in the free YEL3' ion or molecule and hence from the consequences of this geometry for crystal packing. Ab initio (6-31G*) calculations show that the electron density in the region of the LP in an ion is only slightly perturbed by the charge on the counter ion at distances observed in crystals. There is considerable similarity in the electron density distribution in the LP region of Y between free anionic (~0~~~ and free cationic (Me3S+) species. The problem of the so-called stereochemical inertness of the LP in the 14-electron octahedral Y E X~~-ions in crystals is examined in detail. It is concluded that the crystallographic Oh symmetry of the ion in cubic crystals is the result of dynamic averaging of possible orientations of the inherently noncubic YX62-octahedron (cf. the ab initio results for S e~l~~-) .Such averaging also appears to be responsible for the stereochemical "activation" or "inactivation" of the LP in thermally induced crystallographic transitions in the AYX3 halide perovskites and related crystals. To provide a firmer basis for the discussion of the LP, the crystal structures of the five title compounds have been determined. The crystal chemistry of these and related compounds is discussed.Key words: ab initio calculations, Me3S+ and SeC162-; group V trihalides; lone electron pair; trialkylsulfonium salts; VSEPR theory.OSVALD KNOP, ANTHONY LINDEN, BEVERLY R. VINCENT, S. C. CHOI, T. STANLEY CAMERON et RUSSELL J. BOYD. Can. J. Chem. 67, 1984Chem. 67, (1989.En se basant sur les rCsultats d'une analyse dCtaillte de situations typiques dans des cristaux contenant des espkces YEL3', on suggkre que la paire dYClectron libre (E, PL) sur l'atome Y ne dCtermine pas per se la structure cristalline ou I'orientation des unit& Y EL3' dans le cristal. ConsidCrte comme une entitC qui occupe du volume, la PL n'a pratiquement pas de volume effectif intrinskque. Quelles que soient les propriCtCs associCes avec la prCsence de la PL, elles ne sont pas autonomes; elles dCcoulent de l'implication stCrCochimique intrinskque de la PL dans la gComCtrie de et de la distribution de charge dans l'ion ou la molCcule YEL$ libre et ainsi des consCquences de cette gComCtrie sur I'empilement cristallin. Des calculs ab initio (6-3 lG*) dCmontrent que, aux distances observkes dans les cristaux, la densite tlectronique dans la rkgion de la PL d'un ion n'est que ICgkrement perturbCe par la charge du contre-ion. I1 existe une gr...

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“…CsPbCl3 [11,12], CsPbBr3 [10, present work], and CsSnBr3 [2,13,14] have some common features. The parameters of interest regarding the phase transformations are listed in Table 1.…”

Section: Cspbbr3: Phase IIImentioning

confidence: 99%

Phase Transitions in CsSnCl₃ and CsPbBr₃ An NMR and NQR Study

Sharma

Weiden

Weiß

1991

Zeitschrift Für Naturforschung A

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The phase transitions in CsSnCl3 and CsPbBr3 have been studied by X-ray powder diffraction, by 81Br-NQR and by 'H-, 119Sn-, and 113Cs-NMR. At room temperature in air CsSnCl3 forms a hydrate which can be dehydrated to the monoclinic phase II of CsSnCl3. The high temperature phase I has the Perovskite structure, as the X-ray and NMR experiments show. The three phases of CsPbBr3, known from literature, have been corroborated. The results are discussed in the framework of the group ABX3, A = alkalimetal ion, B = IV main group ion, and X = Halogen ion.

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81Br NQR and 119Sn Mössbauer Study for MSnBr3 (M=Cs and CH3NH3)

Cited by 45 publications

References 15 publications

Local Structure and Dynamics in Methylammonium, Formamidinium, and Cesium Tin(II) Mixed-Halide Perovskites from ¹¹⁹Sn Solid-State NMR

Local Structure and Dynamics in Methylammonium, Formamidinium, and Cesium Tin(II) Mixed-Halide Perovskites from ¹¹⁹Sn Solid-State NMR

The lone electron pair and crystal packing: observations on pyramidal YEL₃^ε species, abinitio calculations, and the crystal structures of Me₃SOI, Et₃SI, (Me₃S)₂SnCl₆, (Me₃SO)₂SnCl₆, and (Et₃S)₂SnCl₆

Phase Transitions in CsSnCl₃ and CsPbBr₃ An NMR and NQR Study

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81Br NQR and 119Sn Mössbauer Study for MSnBr3 (M=Cs and CH3NH3)

Cited by 45 publications

References 15 publications

Local Structure and Dynamics in Methylammonium, Formamidinium, and Cesium Tin(II) Mixed-Halide Perovskites from 119Sn Solid-State NMR

Local Structure and Dynamics in Methylammonium, Formamidinium, and Cesium Tin(II) Mixed-Halide Perovskites from 119Sn Solid-State NMR

The lone electron pair and crystal packing: observations on pyramidal YEL3ε species, abinitio calculations, and the crystal structures of Me3SOI, Et3SI, (Me3S)2SnCl6, (Me3SO)2SnCl6, and (Et3S)2SnCl6

Phase Transitions in CsSnCl3 and CsPbBr3 An NMR and NQR Study

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Local Structure and Dynamics in Methylammonium, Formamidinium, and Cesium Tin(II) Mixed-Halide Perovskites from ¹¹⁹Sn Solid-State NMR

Local Structure and Dynamics in Methylammonium, Formamidinium, and Cesium Tin(II) Mixed-Halide Perovskites from ¹¹⁹Sn Solid-State NMR

The lone electron pair and crystal packing: observations on pyramidal YEL₃^ε species, abinitio calculations, and the crystal structures of Me₃SOI, Et₃SI, (Me₃S)₂SnCl₆, (Me₃SO)₂SnCl₆, and (Et₃S)₂SnCl₆

Phase Transitions in CsSnCl₃ and CsPbBr₃ An NMR and NQR Study