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The glass transition and the crystallization kinetics of 70Ge 2 S–10Ga 2 S 3 –20CsCl and 37.5Ge 2 S–22.5Ga 2 S 3 –40CsCl chalcohalide glasses were studied by using a differential scanning calorimeter (DSC) under non-isothermal conditions and X-ray diffraction (XRD) techniques. Two crystalline phases (Ga 2 S 3 and Ge 2 S) were identified after annealing the chalcohalide glasses at the temperature corresponding to the crystallization peaks for 2 h. All the characteristic temperatures such as glass transition (Tg), crystallization onset (Tc) and crystallization peak (Tp) temperatures were found to depend on both the heating rate and the composition. Two approaches, namely Moynihan and Kissinger, were used to calculate the relaxation activation energy (Et). In addition, characteristic activation energies (Ec) and Avrami exponents ( n ) were obtained and analyzed by using Kissinger's relation, Ozawa's method, the Augis–Bennett approximation and the Matusita–Sakka theory.

The atomic structure of chalcogenide glasses in the composition of As35Se60-xTexBi5 (x = 0, 5, 10, 15, 20) is investigated by XRD, Raman spectroscopy and HR-XPS. All results present the consistent evidences on association of Te addition with the structural evolution of glasses. XRD patterns show that the Te can be added into the As35Se60Bi5 system to substitute Se by maximum 15 mol% without causing crystallization. Raman and HR-XPS spectra demonstrate that the substitution of Te for Se is closely related to formation of locally ordered nanostructure in glass network. In low concentration, Te atoms are preferentially bonded with As rather than Bi, forming mixed [AsSe3-xTex] pyramid units. With the increasing of Te content, Te atoms tend to be bonded with Bi to form [BiSe3-xTex] units. In the case of Te incorporation over 20 mol%, the Bi Te bond becomes further strengthened, inducing the precipitation of the sole thermoelectric crystals (Bi2Se3-xTex).

In the present paper, the effects of GeO 2 on properties of GeS 2 –Ga 2 S 3 –CsCl chalcohalide glasses are presented. The absorption spectra, density, microhardness, DSC and the chemical durability are measured. Results show that the addition of GeO 2 remarkably improves the physical and chemical properties of the chalcohalide glass while the visible transmission spectrum is influenced little. The oxy-chalcohalide glass was also used as matrix for doping Tm 3 + (0.1 mol%) which shows the similar NIR luminescence spectrum as the GeS 2 –Ga 2 S 3 –CsCl chalcohalide counterpart. Some interesting structural evolutions are characterized by Raman spectra. The possible mechanism corresponding to the improved properties is discussed.

We report silver metal enhanced near-IR and infrared-to-visible upconversion luminescence in Tm 3+ doped 70GeS 2 –10Ga 2 S 3 –20CsCl (in mol. %) glasses. The metal embedded glasses are prepared under controlled crystallization. Upon 808 nm excitation three fold enhancement of emissions is observed in the visible (446 nm, 496 nm, and 532 nm) and near infrared (1230 nm, 1450 nm and 1480 nm) regions. The possible mechanism responsible for the enhanced luminescence is discussed.

In this paper, Tb3+/Sm3+ co-doped 38B2O3―31Al2O3―31SrO glass was successfully prepared. After heat treatment, single crystal phase SrAl2B2O7 was precipitated from the parent glass. DTA data showed the glass transition temperature at 625 °C and a sharp exothermic peak at 860 °C. XRD patterns demonstrated a regular evolution from glass to glass ceramics with higher treatment temperature and longer treatment time. From the XRD patterns, we supposed that Tb3+/Sm3+ ions can be most likely contained in the crystal phase. The photoluminescence spectra showed that the crystallization can enhance the emission intensity significantly and there could be an optimum crystallization degree to get the strongest luminescence in glass ceramics. The light scattering of devitrification sample can vary the intensity ratio of Sm3+ and Tb3+ emission. Therefore, as a potential route, rare earth ions doped glass ceramics could be a further research direction of luminescence glasses for white light emitting diodes application.

Tm3 + doped GeS2–Ga2S3–CsCl (GGC) chalcohalide glasses are prepared by melt-quenching method. The 1.8 μm emission of Tm3 + is investigated under the excitation of 808 nm laser diode. The ratio of the 1.8 μm emission intensity to that of the 1.48 μm (I1.8/I1.48) reaches 10.7, it is much higher than previously reported Tm3 + doped oxide glasses. With the optimized doping concentration, the 1.8 μm emission in a range of 1756 to 1876 nm shows the largest full-width-at-half-maximum (FWHM) of ~ 120 nm. The life time of Tm3 + reaches millisecond level for the present chalcohalide glasses. It is at the same level as oxide glass counterparts.

A new down-conversion chalcohalide glass ceramics with a composition of 37.5GeS 2 –22.5Ga 2 S 3 –40CsCl (in mol %) doped with 0.15 Eu 2 + and 0.1 Pr 3 + (in mol %) is prepared. The crystallization is characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Ga 2 S 3 crystallites in the nano-scale (20-80 nm) are obtained by the controlled crystallization. Visible photoluminescence properties of the glass and transparent glass ceramics are investigated. The mechanism responsible for the enhanced luminescence of both Eu 2 + and Pr 3 + in the glass ceramics was discussed from the point of view of the reduced phonon energy effect.

In the paper, we report the luminescence behaviors of Eu 2+ -doped chalcohalide glasses. Composition of glass matrix is 37.5GeS 2 -22.5Ga 2 S 3 -40CsCl (mol%) with the concentration of Eu 2+ in the range of 0.1–0.25 (mol%). The optimal Eu 2+ doping concentration was 0.15 mol% at which the glass exhibited an enhanced emission peaking at 434 nm with a full width at half maximum (FWHM) about 80 nm with the excitation at 395 nm.

In the present work, Ce 3+ /Tb 3+ co-doped 60P 2 O 5 -30BaO-10B 2 O 3 phosphate glasses are prepared and their luminescence properties are presented. Under excitation at 303 nm, the Ce 3+ ions singly doped sample show a novel red emission besides the UV one. The co-doped samples show enhanced Tb 3+ ions emission with the increasing of Tb 3+ ions concentration at the cost of Ce 3+ emission. The mechanism of this luminescent behavior is discussed with respect to the relevant energy transfer process.