Red-emissive nanocrystals of Cs₄Mn_xCd_1−xSb₂Cl₁₂ layered perovskites

Abstract

Layered double perovskite are currently investigated as emerging halide-based materials for optoelectronic applications. Herein, we present the synthesis of Cs4MnxCd1-xSb2Cl12 (0 ≤ x ≤ 1) nanocrystals (NCs). X-ray powder diffraction...

Hydrothermal synthesis of stable lead-free Cs4MnBi2Cl12 perovskite single crystals for efficient photocatalytic degradation of organic pollutants

“…S5b, ESI †) on the emission wavelength also confirms that the orange-red emission originates from the relaxation of the same excited state-d-d transition of Mn ions. 36,44 In general, the PL intensity associated with the permanent defects in materials is characterized by a sublinear dependence on the excitation power, and an undesired emission saturation will occur when all defect states are filled. 45 However, in the present case, a linear relationship of excitation power-dependent PL eliminates the possibility of permanent defect-related transition (Fig.…”

Mn2+ as an “Optical Energy Shutter” to Regulate Red‐to‐NIR Luminescence in Rare Earth Doped Layered Quadruple Perovskites

“…The [CdCl 6 ] 4− octahedral layer is sandwiched between two [SbCl 6 ] 3− layers via corner-sharing to form a [SbCl 6 ] 3− -[CdCl 6 ] 4− -[SbCl 6 ] 3− layered quadruple perovskite structure (Figure 1b). [31,32] Through regulating the ratio of Mn 2+ in the precursor, [MnCl 6 ] 4octahedral was formed to replace [CdCl 6 ] 4− in the host lattice. After RE 3+ (RE = Nd, Dy, Ho, Er, Tm, Yb) ions were introduced into the Cs 4 Cd 1−x Mn x Sb 2 Cl 12 QPs, a few of [SbCl 6 ] 3− octahedra were substituted by [RECl 6 ] 3− octahedra.…”

“…Therefore, the PL spectra of Cs 4 Cd 1−x Mn x Sb 2 Cl 12 (0 ≤ x ≤ 1) QPs are excited by 355 nm, and show a broad orange-red emission centered at 608 nm, which comes from the combination of 6 A 1 → 4 T 1 transition of the d-d transition of Mn 2+ magnetic coupling pairs. [32,[35][36][37] With the regulating of Mn-concentration, the PL intensity first increases and achieves optimal PL intensity when the ratio of Mn/(Mn + Cd) is 0.4 in Cs 4 Cd 1−x Mn x Sb 2 Cl 12 and then decreases gradually because of the concentration quenching. [38] To investigate the emission mechanism in these Mn-containing samples, PL lifetime decay curves were carried out at room temperature (Figure 2c).…”

“…As exhibited in Figure 2d, the calculated lifetimes show a decreasing trend from 4.02 ms to 53 μs when Mn-concentration increases because of concentration quenching or self-absorption of denser Mn 2+ ions or Mn-Mn magnetic coupling pairs. [34,32,[39][40][41] Combining the previous study, for Cs 4 Cd 1−x Mn x Sb 2 Cl 12 (0 ≤ x ≤ 1), more Mn ions were incorporated to form different states including the concentration or self-absorption quenching. There are two PL decay pathways among these samples.…”

Lead-Free Halide Perovskite Nanocrystals for Light-Emitting Diodes

“…However, their practical applications have been hindered by their poor luminescence properties. Therefore, research has focused on enhancing the luminescent characteristics of vacancy-ordered quadruple perovskites through metal cation doping [ 124 , 152 , 153 , 154 , 155 , 156 , 157 ]. The synthesis of Cs 4 Cd 1−x Mn x Bi 2 Cl 12 NCs was proposed using a hot-injection method with benzoyl chloride [ 152 ].…”