Cathodoluminescence and photoluminescence in the core region of Bi12GeO20 and Bi12SiO20 crystals

Abstract

Cathodoluminescence and photoluminescence of Bi 12 SiO 20 and Bi 12 GeO 20 samples are studied. Both kinds of samples show a dark orange central part or core. Emissions in the blue, green, and red spectral regions are observed. The 640 nm band is the predominant feature in the core emission. The evolution of this band during electron irradiation suggests possible emission mechanisms. In addition, two infrared emissions at about 915 and 1390 nm are detected.

Study on photoluminescence of thermally treated Bi12GeO20 and Mo:Bi12GeO20 crystals

“…Up to the present, there are some works [9][10][11][12][13][14] about the optical properties of Bi 12 GeO 20 . Cremades [11] studied the luminescence emission of Bi 12 GeO 20 under low temperature (below 200 K) and discovered an emission band centered at about 640 nm.…”

“…Cremades [11] studied the luminescence emission of Bi 12 GeO 20 under low temperature (below 200 K) and discovered an emission band centered at about 640 nm. He also investigated cathodoluminescence of thermal treated and laser irradiated Bi 12 GeO 20 and detected that annealing of Bi 12 GeO 20 caused the appearance of an emission band at 390 nm [12].…”

Influence of femtosecond pulsed laser irradiation on bismuth germanium oxide single crystal properties

“…Thermally stimulated currents as a function of both the temperature at which the crystals are photoexcited and the density of energy used to photoexcite them were reported in [18]. Influences of laser irradiation, thermal treatment [22], and electron beam [23] on luminescence of Bi 12 GeO 20 are reported. Photo-induced absorption in Bi 12 TiO 20 was thoroughly studied in [29], whereas significant influence of doping and annealing on transmission and absorption of BGO were addressed in [16] and [19].…”

“…The properties of non-doped as well as doped Bi 12 GeO 20 were investigated and reported in a number of studies, for example in [13][14][15][16][17][18][19][20][21]. Characteristics of Bi 12 GeO 20 single crystals after exposure to thermal treatment [16][17][18][19]22], to beams of electrons [23], uranium ions [24], fluorine ions [15], g-ray [19] or light [9,18,22,[25][26][27][28] were investigated. Nonlinear properties of Bi 12 GeO 20 crystals were measured with pulsed laser beams in the nanosecond range in [9], whereas in [26][27][28] BGO crystals were irradiated by picosecond laser pulses.…”

Luminescence study of thermal treated and laser irradiated Bi12GeO20 and Bi12SiO20 crystals

“…Changes on the defect structure of Bi 12 GeO 20 ͑BGO͒ and Bi 12 SiO 20 ͑BSO͒ crystals induced by thermal treatments and laser irradiation have been studied by means of cathodoluminescence in the scanning electron microscope. The results have been compared to those previously reported for untreated and electron irradiated samples and recombination mechanisms responsible for some of the observed luminescence bands are discussed.…”