Transient and near‐edge absorption in YVO₄ crystals

Abstract

The process of near-edge absorption annealing in air was studied up to 1500C in YVO 4 . In this annealing process, two stages with activation energies of 0.16 eV and 0.38 eV were obtained. (Should combine to make this one paragraph)In addition to the annealing study, the transient absorption induced by pulsed electron beam excitation (270 keV, 8 ns) was completed on a set of YVO 4 samples with different nearedge absorption levels in the spectral region 3.2-3.5 eV. The spectral range from ~1.25 eV up to 3.0 eV is covered by strong transient absorption. Transient absorption spectra show at least three broad overlapping bands (~1.3 eV, ~2.0 eV and ~3.0 eV). The 3 eV peak position is close to the near-edge absorption band and correlation between transient absorption bands and absorption due to stable colour centers was studied. It is suggested that absorption bands at ~1.3 eV and ~2.0 eV are due to electron and hole polarons, correspondingly.

Synthesis, crystal structure and luminescent properties of pyrovanadates A2CaV2O7 (A=Rb, Cs)

“…Despite the large number of publications about luminescence properties of vanadates [1][2][3][4][5][6][7][8][9][10][11][12], the available experimental and theoretical data are not sufficient to give a unifying explanation of the nature of the luminescence centers in these compounds. There have been attempts to explain the nature of the bands in the optical spectra of vanadates by the presence of vanadium-oxygen clusters such as [VO 4 [12] (Table 4)).…”

“…Complex vanadium oxide compounds have drawn the attention of researchers and developers as promising luminescent materials [1][2][3][4][5][6][7][8][9][10][11][12]. The technical applications of vanadium oxides compounds have been proved by dozens of patents [5,6].…”

“…On the basis of complex vanadium oxides different luminescence materials have been developed and suggested, such as phosphors for plasma display panels and field-emission displays (YVO 4 :Eu) [2,3,5,6] or active laser media (YVO 4 :Ln (Ln ¼ Nd, Er, Tm, Ho)) [7][8][9][10], Ca 3 (V-O 4 ) 2 :Nd 3þ [4]. Effective and advanced crystals for diode pumped lasers can be made from YVO 4 :Nd 3þ [9,10] while luminescent screens with various luminescence spectra [3,[5][6][7][8][9][10][11][12] can be made from (Y, Gd, Lu)VO 4 , dark blue, l ¼ 470-480 nm [3], ScVO 4 , green, l ¼ 510-520 nm [3] and LuVO 4 , red , l ¼ 600-610 nm [3].…”

Influence of Annealing and Irradiation by Heavy Ions on Optical Absorption of Doped Lithium Niobate Crystals

“…It is known that annealing of the oxide crystals in different atmospheres can change the optical absorption of the crystals [2][3][4]. Annealing can produce new point defects, for example oxygen vacancies or removing existing defects, and also can lead to the charge change of point defects or dopants [2,4].…”

“…Annealing can produce new point defects, for example oxygen vacancies or removing existing defects, and also can lead to the charge change of point defects or dopants [2,4].…”