Luminescence and scintillation properties of La- and La,Ag-doped CsPbCl₃ single crystals

Abstract

We analyzed the luminescence and scintillation properties of CsPbCl3 single crystals. La and Ag were chosen as the dopants, although Ag proved to have little effect on the scintillation properties. In the photoluminescence spectra, in addition to the free exciton band at 425 nm, an additional band was observed at 440 nm at low temperatures for the La-doped crystals. The scintillation spectrum of the undoped crystal was composed of the free exciton band and a broad band at 600 nm, which is ascribed to lattice defects. The La doping strongly suppressed both the broad band and the slow scintillation component, which is ascribed to the emission at lattice defects.

Boosting the Er3+ 1.5 μm Luminescence in CsPbCl3 Perovskite Nanocrystals for Photonic Devices Operating at Telecommunication Wavelengths

“…It should be pointed out that Yb 3+ contamination can be excluded for this emission band due to the absence of such peak after Lu 3+ doping (see Figure S4). Interestingly, increasing the Er 3+ concentration leads to a progressive suppression of this emission band (see Figure S2), which may be related to intrinsic deep traps in CsPbCl 3 NCs, such as Cl vacancies or undercoordinated Pb atoms. , A similar NIR emission at 930 nm assigned to the defective states of oxygen vacancies in Fe-doped SrSnO 3 perovskite was also noticed by Muralidharan et al Cl vacancies are commonly observed in perovskite materials and seen as a predominant source of electron trapping. , However, such vacancies can be removed by B-site doping with divalent metal ions − or trivalent lanthanide ions, which favor the introduction of negatively charged Cl – ions for charge compensation . To verify that the quenching of the 994 nm emission band by Er 3+ incorporation can be ascribed to the removal of defects rather than to the activation of additional energy-transfer pathways, we extended our analysis to Lu 3+ -doped CsPbCl 3 NCs as reference.…”

“…Although we detected Er 3+ ions in purified CsPbCl 3 NCs, Er 3+ -doped NCs exhibit only a faint Er 3+ emission at ∼1.54 μm in concentrated samples (see Figure S2), which suggests a weak Er 3+ sensitization. For both undoped and Er 3+ -doped CsPbCl 3 NCs, we observed a NIR emission feature centered at 994 nm with a full width at half-maximum (fwhm) of ∼55 nm, whereas a defect-related visible emission around 600 nm was observed by Watanabe et al This 994 nm emission has a broad excitation profile that closely resembles the excitation profile of the CsPbCl 3 band-edge emission (see Figure S3). The above result indicates that the 994 nm emission band originates from a state directly fed by the band-edge electron–hole pairs.…”

“…34,35 However, such vacancies can be removed by B-site doping with divalent metal ions 36−38 or trivalent lanthanide ions, which favor the introduction of negatively charged Cl − ions for charge compensation. 30 To verify that the quenching of the 994 nm emission band by Er 3+ incorporation can be ascribed to the removal of defects rather than to the activation of additional energy-transfer pathways, we extended our analysis to Lu 3+ -doped CsPbCl 3 NCs as reference. Lu 3+ ions (r = 86.1 pm) 39 are optically silent and have a smaller ionic radius than Yb 3+ (86.8 pm) 39 and Er 3+ (89.0 pm), 39 so they can be favorably doped into the CsPbCl 3 matrix without affecting its optical properties.…”

Picosecond Quantum Cutting Generates Photoluminescence Quantum Yields Over 100% in Ytterbium-Doped CsPbCl3 Nanocrystals

“…No other emission is observed from the La 3+ :CsPbCl 3 NCs. A similar trap PL band has been reported for La 3+ :CsPbCl 3 single crystals, suggesting that this is an internal lattice defect not associated with the NC surfaces. This trap luminescence in these La 3+ :CsPbCl 3 NCs is very bright below ∼80 K, but increasing the temperature above ∼80 K causes excitonic PL to grow in at the expense of the broad trap PL, and the overall PL decreases substantially (see the Supporting Information for additional data).…”

New Intrinsic Scintillator with Large Effective Atomic Number: Tl2HfCl6 and Tl2ZrCl6 Crystals for X-ray and Gamma-ray Detections

“…Moreover, the TLYC crystal can distinguish gamma-ray and neutron radiations by pulse shape discrimination (PSD). (9) Presently, our group has also reported some new halide scintillator materials with low hygroscopicity and large Z eff values, namely, CsPbCl 3 , (10) Cs 3 BiCl 6 , (11) Rb 2 HfCl 6 , (12) TlMgCl 3 , (13) TlCdCl 3 , (14) and Cs 2 HfBr 6 . (15) In particular, Rb…”