화학공학소재연구정보센터
Korean Journal of Materials Research, Vol.21, No.4, 192-195, April, 2011
전착법에 의한 p-형 SbxTey 박막 형성 및 열전특성 평가
Electrodeposition and Characterization of p-type SbxTey Thermoelectric Thin Films
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The electro-deposition of compound semiconductors has been attracting more attention because of its ability to rapidly deposit nanostructured materials and thin films with controlled morphology, dimensions, and crystallinity in a costeffective manner (1). In particular, low band-gap A2B3-type chalcogenides, such as Sb2Te3 and Bi2Te3, have been extensively studied because of their potential applications in thermoelectric power generator and cooler and phase change memory. Thermoelectric SbxTey films were potentiostatically electrodeposited in aqueous nitric acid electrolyte solutions containing different ratios of TeO2 to Sb2O3. The stoichiometric SbxTey films were obtained at an applied voltage of .0.15V vs. SCE using a solution consisting of 2.4 mM TeO2, 0.8 mM Sb2O3, 33 mM tartaric acid, and 1M HNO3. The stoichiometric SbxTey films had the rhombohedral R3m structure with a preferred orientation along the [015] direction. The films featured hole concentration and mobility of 5.8 × 1018/cm3 and 54.8 cm2/V·s, respectively. More negative applied potential yielded more Sb content in the deposited SbxTey films. In addition, the hole concentration and mobility decreased with more negative deposition potential and finally showed insulating property, possibly due to more defect formation. The Seebeck coefficient of as-deposited Sb2Te3 thin film deposited at .0.15V vs. SCE at room temperature was approximately 118 μV/K at room temperature, which is similar to bulk counterparts.