Devitrification Characteristics of the Semiconductor System

The devitrifieation kinetics in the system (1-- x)As2Se~-xSb2Se3 were studied as a function of temperature (69~176 and composition (x = 0.1-0.5). The activation energy of the linear growth rates of relatively large rectangular platelet-l ike crystals in the vitreous matrix was found to be 38 kcal/mole for x = 0.1 and 50 kcal/mole for x = 0.3, 0.4, and 0.5. Along the long dimension of the platelets the growth rate was found to be three times greater than that along the short dimension. Along this long dimension the growth rate increased about three orders of magnitude in going from x = 0.1 to x = 0.5. The number of crystals formed in the vitreous matrix per unit area increased with increasing Sb2Se3 content. The chemical composition of the crystals formed by devitrification was found to be different han that of the surrounding matrix. Quantitative lectron microprobe analysis and scanning electron microscopy showed that the Sb content was higher in the crystals than in the surrounding matrix. Crystals grown directly from the melt (b