Luminescence of CsCaCl3 single crystals

Confinement-enhanced stimulated emission in microcrystalline CsPbCl3 films grown from the amorphous phase

“…5) and S (2.981 eV in Fig. 5) band, we obtain E b ¼ 63 meV, which is comparable to the reported free-exciton binding energies of CsPbCl 3 , 60 -67 meV [10,12,15]. We note here that confinement-induced blue shift of exciton energy measured for CsPbCl 3 microcrystals with radius 2.8 nm (about three times the CsPbCl 3 bulk exciton radius, 0.98 nm [12]) embedded in a Rb 0.95 Cs 0.05 Cl crystal matrix is 84 meV [16] as compared with 21 meV for Figs.…”

“…The blue shift of the emission peak for levels 1-6, relative to that for level 7, gives a measure for the mean size of the microcrystals. In the weak confinement regime of the exciton, the mean effective radius of the microcrystals, R, can be estimated by the relation DE ¼ _ 2 p 2 =ð2mR 2 Þ [11] from the blue shift DE, yielding the values R ¼ 4:5; 5:0; 5:4; 5:7; 6:0 and 7.7 nm for the increasing size levels 1-6, where we use the reduced exciton mass m ¼ 0:65m 0 [12] (m 0 is the electron mass); the R values are large compared with the exciton radius, 0.98 nm [12], enough to meet the assumption of the weak confinement. On the other hand the mean size for the polycrystalline state (level 7) is 25 nm as determined by the Warren analysis of the X-ray diffraction peak.…”

Extended versus Localized Electronic States in Amorphous TlX and CsPbX3 Films (X = Br, Cl) Studied by Optical Absorption Measurements

“…3. Comparison of fundamental absorption spectra of TlCl (upper half, from [1]) and CsPbCl 3 (lower half, from [16]), measured at 77 K for the amorphous (a) and crystallized (c) films. For CsPbCl 3 , spectrum a is decomposed into two Gaussian bands, G 1 and G 2 , with the remainder (a minus G 1 minus G 2 ) as the background absorption (B)…”

The spectral luminescence characteristicsof RbPbCl3 : Cs crystals in the 4–20 eV region

“…This feature is not characteristic of many other crystals. The presence of the anomalous shift is seen clearly when studying the temperature dependence of the spectral location of the reflection exciton peak and the resonance exciton luminescence [12]. Both the reflection exciton peak and the emission band of the CsPbCl 3 single crystal shift towards lower energies as the temperature decreases in spite of the unit cell constants becoming smaller.…”

“…According to theoretical estimation [13], a shortening of the decay time for the microcrystalline inclusions would be observed when the diameter of the inclusions is d ≤ 10r ex , where r ex is the exciton radius of the corresponding single crystal. The diameter of CsPbCl 3 microinclusions is not larger than 10 nm, since r ex for the CsPbCl 3 single crystal is equal to 9.8 Å [12].…”