Continuous‐Flow Synthesis of Orange Emitting Sn(II)‐Doped CsBr Materials

Abstract

display technologies, [1][2][3][4][5][6] but their commercialization still faces significant challenges, as the toxicity of carcinogenic lead metal. [7,8] As a suitable alternative, ongoing research is carrying out on leadfree metals such as Sn, Bi, Ag, Cu, In, and Sb-based perovskites and double perovskites, which also has proven their exceptional optoelectronic properties and promising solar to power energy conversion efficiencies. [9][10][11][12][13][14][15][16][17][18] Among the different halide perovskites the fully inorganic are receiving an increasing attention due to their higher stability. [19,20] All-inorganic cesium tin halides present a variety of compositions, viz. CsSnX 3 , Cs 4 SnX 6 , Cs 2 SnX 6 have been explored with good optoelectronic properties and photovoltaics. [21][22][23] Importantly, Sn(II) is isovalent to Pb(II) and CsSnX 3 /Cs 4 SnX 6 is isostructural with CsPbX 3 /Cs 4 PbX 6 . Hence tin can be considered as a satisfactory replacement to explore lead-free metal halide perovskites and analogues. [24] Unfortunately, there is a limitation in tin-based perovskites owing to the oxidation of Sn 2+ to Sn 4+ upon exposure to ambient air and moisture, which degrades the material by creating trap states that irreversibly collapse the optical emission (and/or carrier lifetimes) of the material. This phenomenon somehow limits the commercial applicability of tin-based perovskites. To overcome this issue, the replacement of Sn 2+ by Sn 4+ was proposed as an alternative to get Cs 2 SnX 6 with high valency of tin (Sn 4+ ). This typical structure of perovskites is referred to as vacancy-ordered double perovskites. [25] In light of the emissive nature of the corresponding tin halide perovskites, CsSnX 3 exhibits an excitonic emission with narrow full-width-half-maximum (FWHM). Unfortunately, they possess a very low photoluminescence quantum yield (PLQY) in comparison to the lead halide perovskites. [26] However, current sign of progress on 0D tin halide perovskites have jumped up to importance in the field of optoelectronics due to their satisfactory photoluminescence with broad coverage across the visible region. [23] Recently, several reports on 0D Cs 4 SnBr 6 published portraying a self-trapped excitonic (STE) emission originated from the isolated [SnBr 6 ] 4octahedra. [27][28][29][30][31] Typical characteristics of STE emissions are i) broad emission and ii) large stokes shift. [32] Hence, the generation of white light due to covering a broad optical window and the reabsorption-related An ongoing demand toward lead-free all-inorganic cesium metal halide perovskites has presented Sn(II) as an ideal substitute of Pb(II) for applications in optoelectronic devices. The major concern regarding Sn(II) is the instability due to the ambient oxidation to Sn(IV). To expand the scope of traditional perovskite and analogues, herein the synthesis and optical performance of Sn(II)-doped CsBr, a new material formed by interstitial doping of Sn(II) into the CsBr matrix, are reported for the first time. This materia...

Superstable CsxSnBrx+2@CsBr Nanocrystals with Over 1200 h of Half-Value PLQY in Air

“…The highest peak in the XRD of NCs is located at 29.3°, and the highest peak in the XRD CsBr is present at 29.5°, which corresponds to a lattice space of 0.30 nm. It is inferred that Sn 2+ incorporation leads to a lattice expansion of CsBr, which is consistent with previous research . The TEM diffraction points accord well with the XRD results, which demonstrates the highly crystalline nature of the NCs.…”

“…It is inferred that Sn 2+ incorporation leads to a lattice expansion of CsBr, which is consistent with previous research. 27 The TEM diffraction points accord well with the XRD results, which demonstrates the highly crystalline nature of the NCs.…”

Highly efficient and stable Cs3Mn0.93Zn0.07Br5@SiO2 for wide color gamut backlight displays

“…For example, CsSnX 3 (X = Br, I) was synthesized by replacing Pb 2+ with Sn 2+ . 16,17 However, Sn 2+ is easily oxidized to Sn 4+ . On the other hand, double perovskites composed of monovalent metal ions and trivalent metal ions such as Cs 2 AgBiX 6 (X = Cl, Br) [18][19][20] and Cs 2 AgInCl 6 , 21,22 have also been reported.…”