摘要
The results of experimental investigation of n-type semiconductor based on Bi2Te3 alloy were presented. This material is used in manufacture of thermoelectric coolers and electrical power generation devices. BizTe2.88Se0.12 solid solution single crystal has been grown using the Czochralski method. Monitoring of structure changes of the sample was carried out by electron microscope. The elemental composition of the studied alloy was obtained by energy dispersive spectrometry (EDS) analysis and empirical formula of the compound was established. X-ray diffraction analysis confirmed that the Bi2Te2.88Se0.12 sample was a single phase with rhombohedral structure. The behavior upon heating was studied using differential thermal analysis (DTA) technique. Changes in physical and chemical properties of materials were measured as a function of increasing temperature by thermogravimetric analysis (TGA). The lattice parameters values obtained by X-ray powder diffraction analyses of Bi2Te2.88Se0.12 are very similar to BizTe3 lattice constants, indicating that a small portion of tellurium is replaced with selenium. The obtained values for specific electrical and thermal conductivities are in correlation with available literature data. The Vickers microhardness values are in range between HV 187 and HV 39.02 and decrease with load increasing. It is shown that very complex process of infrared thermography can be applied for characterization of thermoelectric elements and modules.
研究基于Bi2Te3合金的n型半导体的实验制备。该材料可用于制备热电散热器和发电设备。采用Czochralski法制备Bi2Te2.88Se0.12固溶单晶体。采用电子显微镜研究样品的组织变化。利用EDS分析实验合金的成分,并确立化合物的经验分子式。XRD表明Bi2Te2.88Se0.12样品为具有斜方六面体结构的单晶。利用差热分析研究合金的加热行为。利用热重分析研究材料的物理和化学性能随温度的变化。从XRD分析得到的Bi2Te2.88Se0.12晶格参数与Bi2Te3的非常相近,表明只有少部分Te被Se取代。所得的单晶的比电导率和比热导率与已有数据相符。所得维氏显微硬度为HV 187~39.02,且随着载荷增加,硬度降低。结果表明可以采用红外热成像法对热电元件和模块进行表征。
基金
"Development of ecological knowledge-based advanced materials and technologies for multifunctional application" (Grant No.TR34005)
"New approach to designing materials for energy conversion and storage" (Grant No.OI172060)
"0-3D nanostructures for application in electronics and renewable energy sources:synthesis,characterisation and processing" (Grant No.III45007)