Synthesis and Optical Properties of Mn2+-Doped Amino Lead Halide Molecular Clusters Assisted by Chloride Ion.
03 Aug 2021-Journal of Physical Chemistry Letters (American Chemical Society (ACS))-Vol. 12, Iss: 31, pp 7497-7503
TL;DR: In this paper, a model for the formation of perovskite nanostructures was proposed to explain the formation mechanism of Mn2+-doped MCs with the help of time-resolved PL, Fourier transform infrared, and electron paramagnetic resonance results.
Abstract: Mn2+-doped amino lead halide molecular clusters (MCs) are synthesized using amine (e.g., n-octylamine, or butylamine) as passivating ligand and MnX2 (X = Cl or Br) as the Mn2+ doping source at room temperature. Their optical properties are investigated with UV-visible absorption, photoluminescence (PL), and PL excitation spectroscopy. The Mn2+ precursor plays a vital role in the synthesis of Mn2+-doped MCs. MnCl2 seems to facilitate the incorporation of Mn. The MnCl2 doping causes electronic absorption blue shift and leads to a spin-forbidden 4T1 → 6A1 Mn d-electron emission. With the help of time-resolved PL, Fourier transform infrared, and electron paramagnetic resonance results, a model is proposed to explain the formation mechanism. We suggest that Mn2+ doping replaces Pb2+ is assisted by Cl- ions that replace Br- ions. This study demonstrates the possibility of doping MCs and has important implications in gaining new fundamental insight into the growth mechanisms of perovskite nanostructures.
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TL;DR: In this article , the impact of different molecular ligands on the surface passivation and interconversion of metal halide perovskite quantum dots and magic sized clusters (PMSCs) is discussed.
Abstract: Metal halide perovskite quantum dots (PQDs) and perovskite magic sized clusters (PMSCs) exhibit interesting size- and composition-dependent optoelectronic properties that are promising for emerging applications including photovoltaic solar cells and light-emitting diodes (LEDs). Much work has focused on developing new synthesis strategies to improve their structural stability and property tunability. In this paper, we review recent progress in the synthesis and characterization of PQDs and PMSCs, with a focus on the impact of different molecular ligands on their surface passivation and interconversion. Moreover, the effect of capping ligands on ion exchange during synthesis and doping is discussed. Finally, we present some perspectives on challenges and opportunities in fundamental studies and potential applications of both PQDs and PMSCs.
13 citations
05 Oct 2022
TL;DR: In this paper , a hexagonal Mn2+-doped CsCdCl3 perovskite crystal was reported to have stable photoluminescence (PL) at both high temperature and humidity.
Abstract: Halide perovskite has been widely studied as a new generation of photoelectronic materials. However, their thermal and humidity-induced emission quenching have greatly limited their utility and reliability. Here, we report a hexagonal Mn2+-doped CsCdCl3 perovskite crystal that possesses stable photoluminescence (PL) at both high temperature and humidity. The room temperature long-persistent luminescence (LPL) of the single crystals lasts up to 1480 s and can be adjusted by changing the concentration of Mn2+ ion doping. The characteristic emission of d-d transition of Mn2+ is realized, and the photoluminescence quantum yield (PLQY) is up to 91.4%, it can maintain more than 90% of the initial PL spectral integral area at 150 °C (423 K). High humid stability PL can be achieved more than 75% of the initial PL intensity after 55 days of immersion in water. These excellent properties show the application prospect of the LPL material in lighting indication and anti-counterfeiting.
10 citations
TL;DR: In this article , a layered structural model is proposed for nonsmallized molecular clusters with a BTYA ligand capping on the surface of the corner-shared tilted [PbBr6]4- octahedral framework.
Abstract: Nanosized molecular clusters (MCs) composed of PbBr2 and neutral ligand butylamine (BTYA) with unique optical properties in solution and solid states have been synthesized using ligand-assisted reprecipitation and spin-coating, separately. The studies of their optical properties using ultraviolet-visible (UV-vis) absorption and photoluminescence (PL) show the first electronic absorption and PL band of the MCs at 401 and 411 nm, respectively, for the solution and solid state samples that exhibit good stability under ambient conditions. Low-temperature PL spectra below 30 K show vibronic peaks indicative of a single size or a very narrow size distribution of the MCs. On the basis of Raman, X-ray diffraction, and transmission electron microscopy measurements, a layered structural model is proposed for the MCs with a BTYA ligand capping on the surface of the corner-shared tilted [PbBr6]4- octahedral framework. The stable and retained structure of MCs in the solid state is promising for photonics applications.
3 citations
TL;DR: In this article , it was shown that the near 400 nm band originates from ligand-passivated lead bromide molecular clusters (PbBr2 MCs), which do not contain the A component of the ABX3 perovskite structure.
Abstract: In the synthesis of cesium lead bromide (CsPbBr3) perovskite quantum dots, with an electronic absorption and emission band around 510 nm, and perovskite magic-sized clusters (PMSCs), with an electronic absorption and emission band around 430 nm, another distinct absorption and emission around 400 nm is often observed. While many would attribute this band to small perovskite particles, here we show strong evidence that this band is a result of the formation of lead bromide molecular clusters (PbBr2 MCs) passivated with ligands, which do not contain the A component of the ABX3 perovskite structure. This evidence comes from a systematic comparative study of the reaction products with and without the A component under otherwise identical experimental conditions. The results support that the near 400 nm band originates from ligand-passivated PbBr2 MCs. This observation seems to be quite general and is significant in understanding the nature of the reaction products in the synthesis of metal halide perovskite nanostructures.
2 citations
TL;DR: In this paper , a hexagonal Mn2+-doped CsCdCl3 perovskite crystal was reported to have stable photoluminescence (PL) at both high temperature and humidity.
Abstract: Halide perovskite has been widely studied as a new generation of photoelectronic materials. However, their thermal and humidity-induced emission quenching have greatly limited their utility and reliability. Here, we report a hexagonal Mn2+-doped CsCdCl3 perovskite crystal that possesses stable photoluminescence (PL) at both high temperature and humidity. The room temperature long-persistent luminescence (LPL) of the single crystals lasts up to 1480 s and can be adjusted by changing the concentration of Mn2+ ion doping. The characteristic emission of d-d transition of Mn2+ is realized, and the photoluminescence quantum yield (PLQY) is up to 91.4 %, it can maintain more than 90 % of the initial PL spectral integral area at 150 °C (423 K). High humid stability PL can be achieved more than 75 % of the initial PL intensity after 55 days of immersion in water. These excellent properties show the application prospect of the LPL material in lighting indication and anti-counterfeiting.
1 citations
References
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TL;DR: By elucidating the role of relative bond strengths within the precursor and the host lattice, this work develops an effective approach for incorporating manganese (Mn) ions into nanocrystals of lead-halide perovskites (CsPbX3, where X = Cl, Br, or I).
Abstract: Impurity doping has been widely used to endow semiconductor nanocrystals with novel optical, electronic, and magnetic functionalities. Here, we introduce a new family of doped NCs offering unique insights into the chemical mechanism of doping, as well as into the fundamental interactions between the dopant and the semiconductor host. Specifically, by elucidating the role of relative bond strengths within the precursor and the host lattice, we develop an effective approach for incorporating manganese (Mn) ions into nanocrystals of lead-halide perovskites (CsPbX3, where X = Cl, Br, or I). In a key enabling step not possible in, for example, II–VI nanocrystals, we use gentle chemical means to finely and reversibly tune the nanocrystal band gap over a wide range of energies (1.8–3.1 eV) via postsynthetic anion exchange. We observe a dramatic effect of halide identity on relative intensities of intrinsic band-edge and Mn emission bands, which we ascribe to the influence of the energy difference between the cor...
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