| Summary: | 碩士 === 國立東華大學 === 材料科學與工程學系 === 96 === In this study. Se-incorporated As2Te3 crystals, As2(SexTe1-x)3 (x=
0.05 , 0.10 , 0.15 , 0.2), were grown by vertical Bridgman method. The
crystalline structure and stoichiometry for these crystals were investigated
by X-ray diffraction, SEM, Raman spectroscopy and EPMA techniques.
The thermoelectric properties for these compounds were studied by
means of thermal and carrier transport measurement in the temperature
range between 150K to 300K. Electrical property of the as-grown
samples was characterized using room temperature resistivity and Hall
measurement. Temperature dependence of resistivity, Seebeck coefficient
and thermal conductivity for the various compositions of these crystals
were analyzed. The energy band gap of these crystals were examined by
thermoreflectance measurements.
The values of energy band gap (Eg) of As2(SexTe1-x)3 (x= 0.05 , 0.10 ,
0.15 , 0.2) with can be fitted by an analytical expression
Eg= 0.99 + 2.206x +9.62 x2
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