Tunable Efficient White Emission in Holmium Doped Double Perovskites Cs₂KInCl₆ via Antimony Sensitization

Abstract

lead-free double perovskites of Cs 2 M(I) M(III)X 6 have drawn extensive attention and are seen as a promising alternative for LHPs. [3] The double perovskites are characterized by a 3D framework of alternating and corner-shared M(I)X 6 and M(III)X 6 octahedra. Particularly, although a great variety of double perovskites have been reported, only a few of them, such as Cs 2 NaInCl 6 , Cs 2 KInCl 6 , Cs 2 AgSbCl 6 , and Cs 2 AgBiBr 6 , have fascinating photoelectric characteristics. [4] Nevertheless, the double perovskites generally exhibit an unsatisfying photoluminescence efficiency, which is caused by their indirect bandgap characteristics or parity-forbidden transition in the direct bandgap system. [5] Hence, it is a great challenge to obtain double perovskites with highly efficient emission.Metal ion doping has been demonstrated to be a robust strategy to regulate the optical properties of LHPs, and has also achieved impressive results in double perovskites. For example, Sb 3+ doped Cs 2 NaInCl 6 shows a blue emission with a PLQY of 75.89%, [6] Sb 3+ doped Cs 2 KInCl 6 emits a cyan emission with a PLQY of 99.2%, [7] Bi 3+ doped Cs 2 (Ag 0.6 Na 0.4 )InCl 6 shines white emission with a PLQY of 86%, [8] Mn 2+ doped Cs 2 Na 0.2 Ag 0.8 InCl 6 shows a red emission with a PLQY of 32%. [9] Although single-doping technology of double perovskites can achieve efficient emission in the visible light range and has made significant progress in solid-state lighting (SSL), its further development is undoubtedly limited by its un-tunable emission and single scope of application. Recent works have suggested that co-doping strategy can provide multiple emission centers in a single compound, which endows double perovskites to have abundant optical properties, and can further develop its applications in multifunctional materials. For instance, Bi 3+ /Sb 3+ co-doped Cs 2 Ag 0.1 Na 0.9 InCl 6 exhibits a distinct excitation-wavelength dependent emission characteristic, which makes it show great potential in optical anti-counterfeiting. [10] More particularly, ns 2 metal ions (M 3+ = Bi 3+ and Sb 3+ ) can work as a sensitizer of Ln 3+ (Ln = Yb, Er, Nd), and construct an appropriate energy-transfer channel from ns 2 electrons to Ln 3+ , thus ultimately boosting the nearinfrared emission (NIR) of Ln 3+ . [11] Typical examples are that the NIR emission intensity of Bi 3+ /Er 3+ and Bi 3+ /Yb 3+ co-doped Cs 2 AgInCl 6 is about 45 and 27 times higher than that of single Recently, ns 2 metal ions (such as Bi 3+ and Sb 3+ ) doped double perovskites have captured intense attention for their efficient emission, however, achieving efficient and tunable white light emission is always an enormous challenge. Herein, Sb 3+ /Ho 3+ co-doped Cs 2 KInCl 6 double perovskites are proposed, and the photoluminescence results show that there are two emission bands, one broad cyan emission band stems from self-trapped exciton (STE) in [SbCl 6 ] 3octahedron, while another red emission band derives from the f-f transitions of Ho 3+ . The emission processes ...

Multimode Luminescence Tailoring and Improvement of Cs2NaHoCl6 Cryolite Crystals via Sb3+/Yb3+ Alloying for Versatile Photoelectric Applications

“…[16] The doping of these main group ions can enhance the luminescence intensity and improve the PLQY of materials effectively. Notably, incorporating rare-earth (RE) ions into perovskites has remarkable optical characteristics, including sharp emission peaks, exceptional photochemical stability, multi-level emission, and up-conversion luminescence (UCL), [17][18][19][20] which have a wide range of applications in anti-counterfeiting, [21][22][23] biomedicine, [24][25][26] light-emitting diodes [27][28][29][30] and a combination of them. For instance, Nag et al incorporated Bi 3 + and Er 3 + into Cs 2 AgInCl 6 to circa 45 times more intense near-infrared (NIR) emission after excitation at 370 nm.…”

Excitation-dependent efficient photoluminescence in an organic–inorganic (C4H12N)2HfCl6 perovskite induced by antimony doping

“…13,14 Chemical doping is an effective strategy for tailoring the electronic and optical properties of metal halides. [15][16][17][18][19][20][21] For example, antimony (Sb 3+ ) ions with ns 2 electronic configurations can be used to confer superb light-emitting properties to materials, typically including efficient broadband STE emission. [22][23][24][25][26][27] For these halide perovskite materials, excitons are absolutely confined in isolated polyhedrons with strong quantum confinement, ultimately producing only a single STE emission at room temperature and no emission of high-energy free excitons (FEs).…”

Achieving Multicolor Emitting of Antimony-Doped Indium-Based Halide Perovskite via Monovalent Metal Induced Phase Engineering

“…Huang et al. achieved white light emission with a photoluminescence quantum yield of up to 90 ± 2% by codoping Cs 2 KInCl 6 with Sb 3+ /Ho 3+ . Gong et al reported that by reacting with water, green emitting Cs 3 InCl 6 :Sb 3+ nanocrystals were converted into orange emitting Cs 2 InCl 5 ·H 2 O:Sb 3+ nanocrystals, with a PLQY of up to 75.3% .…”

“…16 Huang et al achieved white light emission with a photoluminescence quantum yield of up to 90 ± 2% by codoping Cs 2 KInCl 6 with Sb 3+ /Ho 3+ . 17 Gong et al reported that by reacting with water, green emitting Cs 3 InCl 6 :Sb 3+ nanocrystals were converted into orange emitting Cs 2 InCl 5 •H 2 O:Sb 3+ nanocrystals, with a PLQY of up to 75.3%. 18 Yan et al showed that the crystal structure of Mn 2+ -doped Cs 3 BiCl 6 and Cs 3 Bi 2 Cl 9 metal halides could be flexibly and reversibly adjusted by the addition of CsCl and BiCl 3 reactants following the reaction.…”