Luminescence of CsPbCl3 Nanocrystals Dispersed in a CsCl Crystal under High-Energy Excitation

Abstract

The luminescence spectral and kinetic characteristics of CsPbCl 3 nanocrystals, thermally created in a CsCl:Pb single crystal and dispersed in a CsCl matrix, have been studied under excitation by synchrotron radiation in the VUV spectral region (4 to 20 eV). Various components found in the decay kinetics of the 2.98 eV emission have been connected with the direct excitation of the CsPbCl 3 luminescence and with the reabsorption of luminescence of other emitting centers by the CsPbCl 3 nanocrystals. A high-energy shift of the free exciton emission band maximum of the CsPbCl 3 nanocrystals with respect to that observed for a CsPbCl 3 single crystal as well as the shortening of the luminescence decay time are considered from the point of view of quantum size effects.

Luminescent Kinetic Characteristics of Cspbcl_3 Aggregates Dispersed in Rb_{1-X}cs_{x}cl (X=0.05-0.2) Matrices

“…The average sizes of the CsPbCl 3 nanocrystals formed during the similar hightemperature annealing in the Rb 0.95 Cs 0.05 Cl-Pb (C Pb = 1 mole%) and CsCl-Pb (C Pb = 1 mole%) crystals [17] are R QD ≈ 2.8 and 4.7 nm, respectively. This relation between the dimensions of nanocrystals in the Rb 0.95 Cs 0.05 Cl and CsCl matrices is explained by the fact that on decreasing the number of the Cs + ions in the compound, the probability of the Conclusions about the presence of the quantum size effect of the CsPbCl 3 nanocrystals are confirmed by the data concerning their luminescence decay kinetics.…”

Luminescence of Ce doped LaCl3microcrystals incorporated into a single-crystalline NaCl host

“…It would seem that this feature could be caused by the energy transfer from excitons and electron-hole pairs to microparticles. However, in our previous studies of the luminescence properties of CsPbCl 3 nanoparticles embedded in CsCl, RbCl and KCl matrices [11,12] upon the bandto-band excitation the energy transfer from host matrices to nanoparticles was not observed except for cases of intrinsic or impurity emission reabsorption by nanocrystals. The excitation of nanocrystal luminescence was observed only in the range of host matrix transparency due to the direct absorption of light by nanocrystals.…”

Extremely photo-luminescent microcrystalline CsPbX3 (X=Cl, Br) films obtained by amorphous-to-crystalline transformation

“…In the last several years many interesting studies have been carried out on a new type of microcrystals, i.e., CsPbX 3 (X ¼ Cl, Br) microcrystals dispersed in crystal matrices, with the expectation of their possible application in fast scintillators and opto-electronic devices taking advantage of a very fast and strong free-exciton luminescence of the source compounds. The studies are based on the measurements of photoluminescence of the microcrystals thermally grown in Pb 2þ -doped CsX [1][2][3][4][5][6][7][8][9][10][11][12][13] or CsSrX 3 [14] crystals and Cs þ -doped PbX 2 [12,15,16] crystals, and deal with quantum size effects on excitons, such as confinement-induced blue shifts of exciton energy and confinement-induced changes in the decay kinetics of excitons, or aim at elucidation of growth kinetics of the microcrystals. The decay-kinetics studies reveal that the radiative decay time of the free excitons in the microcrystals is further shortened by the effect of confinement on the excitons, suggesting that the inherently strong free-exciton luminescence for CsPbX 3 can be further enhanced in intensity by the confinement effect.…”

“…Therefore, free-exciton spectroscopy is frequently conveniently used for characterizing microcrystals or quantum dots [21]. In fact, in all the existing works which deal with the CsPbX 3 (X ¼ Cl, Br) microcrystals dispersed in crystals [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] or constituting films [17,18], the authors are successful in assessing the microcrystals solely by means of free-exciton spectroscopy. For example, the blue shift of free-exciton energy can be used to estimate the mean size of the microcrystals.…”

“…For example, the blue shift of free-exciton energy can be used to estimate the mean size of the microcrystals. Concerning the mean size of the microcrystals determined by free-exciton spectroscopy on a nm-scale, there has been no independent evidence from structural studies, such as by X-ray diffraction spectroscopy or by electron microscopy, both for the microcrystals dispersed in crystals [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] and for the microcrystals constituting films [17,18].…”