Doping Mn(II) in All-Inorganic Ruddlesden–Popper Phase of Tetragonal Cs₂PbCl₂I₂ Perovskite Nanoplatelets

Abstract

Doping Mn­(II) in inorganic Ruddlesden–Popper phase Cs2PbCl2I2 perovskite nanoplatelets is reported. The host nanostructures were prepared with a calculative protocol taking the exact required composition of Cs­(I) and Pb­(II) and injecting the preformed mixed oleylammonium chlorides and iodides at optimized reaction temperature. Reactions were optimized with various halides and their mixtures, but the stable phase of the Cs2PbX4 system was obtained only for the chloride–iodide mixed-halide system. Introduction of Mn­(II) along with Pb­(II), resulted in successful light-emitting doped nanocrystals. Measuring the photoluminescence and the decay lifetimes at room and liquid nitrogen temperatures, the variations in the excitonic, self-trapped, and Mn dopant emission properties were compared with those of the chalcogenide and perovskite nanocrystals.

Mn2+‐Doped Metal Halide Perovskites: Structure, Photoluminescence, and Application

“…[ 174 ] Surprisingly, Pradhan and co‐workers successfully synthesized the Mn 2+ ‐doped all‐inorganic Cs 2 PbCl 2 I 2 perovskite NPLs (Figure 11c). [ 175 ] Different from 2D organic–inorganic hybrid metal halide perovskites, an additional band‐edge emission located 534 nm is observed in Cs 2 PbCl 2 I 2 NPLs at cryogenic temperatures (Figure 11d). Such an abnormal emission is attributed to the self‐trapped emission, which is similar to the previously reported layered perovskites.…”

“…c) The image of the reaction flask for Mn 2+ ‐doped Cs 2 PbCl 2 I 2 platelet under excitation at 365 nm. [ 175 ] d) PL spectra of Cs 2 PbCl 2 I 2 at room and LN 2 temperature under the excitation at 350 nm. [ 175 ] a,b) Reproduced with permission.…”

“…[ 175 ] d) PL spectra of Cs 2 PbCl 2 I 2 at room and LN 2 temperature under the excitation at 350 nm. [ 175 ] a,b) Reproduced with permission. [ 173 ] Copyright 2019, American Chemical Society.…”

Low‐Dimensional‐Networked Cesium Lead Halide Perovskites: Properties, Fabrication, and Applications

“…However, a weak PLQY is observed for Cs 2 PbI 2 Cl 2 because the combination of possible I segregation and defective Ruddlesden–Popper interfaces. [ 77 ] A further doping and post‐treatment may be a feasible way to promote its photophysical properties and offer new opportunities in a variety of optoelectronic fields. [ 77,78 ]…”

Two‐Dimensional Metal‐Halide Perovskite‐based Optoelectronics: Synthesis, Structure, Properties and Applications

“…Particularly, the photoluminescence emission properties display an obvious dependence on the thickness of the 2D CsPbI 3 nanosheets. Furthermore, Wang et al [ 37 ] and Pradhan et al [ 38 ] successively reported the all‐inorganic 2D perovskites with ordered mixed halides, respectively, are Cs 2 PbCl 2 I 2 (by a solid‐state method) and Mn 2+ ‐doped Cs 2 PbCl 2 I 2 nanosheets (by an acid solution‐assisted method). For the 2D Cs 2 PbCl 2 I 2 perovskites (Figure 1d), density functional theory (DFT) calculations are performed to study the relevant thermodynamic stability of all Cs 2 PbX 4 with possible combinations of mixed halide, and there are nine possible combinations in three types (Figure 1e).…”