Highly Reversible Cesium Manganese Iodine for Sensitive Water Detection and X-ray Imaging

Abstract

Low-dimensional lead (Pb)-free perovskite derivatives have recently been regarded as promising candidates for various optoelectronic applications because of their merits of easy preparation, nontoxicity, and broadband self-trapped exciton emission. However, similar to those Pb-based metal halide perovskites, most of these materials undergo an irreversible structural damage upon exposure to aqueous medium, which imposes restrictions on cyclic utilization in both academic and industrial fields. Herein, we report pure Mn-based metal halide, Cs3MnI5, which readily recovers from aqueous solution under mild heat stress and maintains excellent optical properties with high photoluminescence quantum yields of 73%. Meanwhile, this recyclable halide material demonstrates a sensitive X-ray response with a low detection limit of 0.4 μGy/s, high light yield of 33600 ph/MeV, and spatial resolution of 7.45 lp/mm, being suitable for X-ray imaging.

Lead-free halide Cs2MnCl4:Cu+ as a new phosphor for efficient green light emission

“…The pristine Cs 2 MnCl 4 compound shows a strong absorption at 230, 355, 420, 450 and 510 nm, corresponding to the typical absorption of Mn 2+ ions from 6 A 1g to 4 E d , 4 T 2d , 4 E g / 4 A 1g , 4 T 2g and 4 T 1g , respectively. 25,38 After doping with copper(I), an additional absorption band located at 240-310 nm was observed. Such phenomenon indicates that this large absorption band probably arises from the copper(I) In the of finding the optical band gap of the prepared samples, we have converted the diffuse reflectance spectra into the Kubelka-Munk function using the following equation: 39…”

Zero-Dimensional Hybrid Cuprous Halide of [BAPMA]Cu2Br5 as a Highly Efficient Light Emitter and an X-Ray Scintillator

“…By virtue of the modulation transfer function (MTF) based on the slanted-edge method, the spatial resolution was further evaluated to be 15.79 lp/mm at an MTF value of 0.2, which was better than those of metal halides, such as Cs 2 AgBiBr 6 (4.9 lp/mm), CsCu 2 I 3 (7.5 lp/mm), [Bmpip] 2 CuBrI (5.6 lp/mm), Cs 3 MnI 5 (7.45 lp/mm), (C 8 H 20 N) 2 MnBr 4 (5 lp/mm), etc. (Figure i). ,− These results demonstrate the excellent X-ray scintillation performance of [BAPMA]­Cu 2 Br 5 with potential applications in medical images, X-ray detection, radiography, etc.…”

Regulating the Optical Properties of Cs3MnBr5 Nanocrystals in Glasses for Narrow-Band Green Emission

“…PLE spectra of the precursor and heat-treated Z00 specimens are recorded (Figure c). For heat-treated Z00 specimens, six PLE bands recorded by monitoring the 520 nm PL are found at 328, 364, 384, 438, 454, and 470 nm, assigned to the 6 A 1 → 4 T 2 (P), 6 A 1 → 4 E(D), 6 A 1 → 4 T 2 (D), 6 A 1 → 4 A 1 , 4 E(G), 6 A 1 → 4 T 2 (G), and 6 A 1 → 4 T 1 (G) transitions of Mn 2+ ions in tetrahedral coordination, respectively, consistent with those reported in Mn-based halides, ,, confirming that the narrow-band green PL in heat-treated Z00 specimens (Figure b) are from false[ normalM normaln normalB normalr 4 false] 2 − units in Cs 3 MnBr 5 NCs. PLE spectra recorded by monitoring the PLE at 650 nm from the heat-treated Z00 specimens are almost identical with those recorded by monitoring the green PL at 520 nm (Figure c), revealing that red PL of the heat-treated Z00 specimens is mainly from the false[ normalM normaln normalB normalr 4 false] 2 − units in Cs 3 MnBr 5 NCs, instead of octahedrally coordinated Mn 2+ ions in the glass matrix.…”

“…23−30 At present, Cs 3 MnBr 5 phosphors and colloidal Cs 3 MnI 5 NCs have achieved efficient green PL with PL QYs of 49 and 73%, respectively. 31,32 However, due to the ionic structure, Mn-based halides are sensitive to humidity and oxygen, 33,34 hindering their potential applications. Postsynthetic encapsulation employed to improve the stability generally involves mixing nano-and microcrystalline compounds with organic polymers.…”