Effect of the chemical composition of the matrix on the transmission spectra of CuInS2-activated glasses

Autor: N. P. Solovei, A. P. Molochko, I. V. Bodnar
Rok vydání: 1996
Předmět:
Zdroj: Journal of Applied Spectroscopy. 63:212-216
ISSN: 1573-8647
0021-9037
DOI: 10.1007/bf02606728
Popis: The spectral properties of activated amorphous media (AAM) are determined primarily by the nature, concentration, and state of the semiconductor compound. However, the chemical composition of the initial glass matrix and the extent and character of its interaction with the activator can also exert an effect on the position and form of the absorption edge. As an initial matrix for the synthesis of AAM, lime-silicate glasses, predominantly soda lime glasses, are most often used [1-3 ]. First of all interest in the given system is caused by the fact that its components do not interact with the activator. The positive influence of zinc and boron oxides introduced into this system on the coloration of amorphous media and the position and steepness of the absorption edge has been noted in a number of publications [4, 5 ]. In the present work we investigated the effect of a change in the chemical composition of an initial glass matrix, synthesized in the SiO2-CaO-Na20 system, on the spectral properties of AAM. As an activator we used the ternary semiconductor CulnS2 compound obtained by a procedure described in ]6 ]. Glass formation and the properties of glasses in the SiO2-CaO-Na20 system were studied earlier 17, 8 ]. According to [8 ], a region of transparent glasses on the triangle of compositions is adjacent to the SiO 2 vertex, including the binary. SiO2-CaO and SiO2-Na20 compositions, and is limited to the following contents of the components (mole %): 40-100 SiO2, 0-60 CaO, and 0-40 Na20. Since glasses with SiO2 80 mole %) are high-melting and have high synthesis temperatures in the present investigation the region of the transparent glasses was limited to the following contents of the components (mole %): 65-80 SiO2, 5-30 CaO, and 5-30 Na20 (Fig. 1). The synthesis of AAM was conducted in a gas-fired furnace at a temperature of 1720 + 10 K with a holding time of 1 h at the maximum temperature in a reducing medium. To prevent oxidation of the activator and burn-out of the chalcogen, coal was added to the charge. The CulnS2 semiconductor compound (0.75 mole%) was also directly introduced into the charge in a finely dispersed state. After the synthesis, the specimens were annealed in a muffle furnace at a temperature of 830_+5 K with its subsequent inertial cooling. The transmission spectra were recorded on a Beckman spectropholometer on plane-parallel ~ 2 mm-thick specimens. As the investigations have shown, all the glasses are colored directly during the synthesis and cooling of the melt. However, depending on their location on the glass-formation diagram, inhomogeneities in the form of dilutes and crystal inclusions are visually observed on the surface of the specimens. Their greatest amount is found in the specimens whose compositions are adjacent to the SiO2-CaO line; this can be attributed to both the low temperature of the synthesis and the low c~,stallization stability of the initial glasses.
Databáze: OpenAIRE
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