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本文对适用于室温附近的致冷材料的温差电性质的最近研究结果进行了评述。所讨论的材料包括Bi_2Te_3及其膺二元合金Bi_2Te_3—Sb_2Tc_3和,Bi_2Te_3—Sb_2Se_3,着重讨论膺三元合金系Bi_2Te_3—Sb_2Te_3—Sb_2Se_3。评论的内容有:(1)塞贝克系数、热导率和优值与电阻率的关系;(2)晶格热导率与合金的组份关系;(3)膺三元合金的温差电性质与温度的关系。同时还介绍了生长条件影响合金的温差电性质研究方面所取得的新结果。用膺三元系Bi_2Te_3—Sb_2Te_3—Sb_2Te_3—Sb_2Se_3。能得到最好的N型和P型材料。这些在室温下给出平均优值3.3×10~(-3)度的材料,用做单级致冷电偶对时,在室温能达到78℃最大温差的珀尔帖致冷。此外,由这些膺三元合金制成的六级珀尔帖致冷器,可使温度从300K连续下降到159K。这些合金的温差电性质之所以这样优越,可以用它们的晶格热导率较低而且受温度的影响小,以及掺入Sb_2Se_3后禁带宽度有所增加来加以解释。
In this paper, the recent results of thermoelectric properties suitable for refrigeration materials near room temperature are reviewed. The materials discussed include Bi2Te3 and its binary alloys Bi2Te3-Sb2Tc3 and Bi2Te3-Sb2Se3, focusing on the Bi3Te3-Sb2Te3-Sb2Se3 alloy. The contents of the review are as follows: (1) The Seebeck coefficient, the thermal conductivity and the relationship between the merit and the resistivity; (2) The relationship between the lattice thermal conductivity and the composition of the alloy; (3) The thermoelectric properties of the ternary alloy Relationship with temperature. At the same time, the new results obtained from the research on the influence of growth conditions on the thermoelectric properties of the alloy were introduced. Use Ying ternary system Bi 2 Te 3-Sb 2 Te 3-Sb 2 Te 3 Sb 2 Se 3. Can get the best N-type and P-type materials. These give a mean value of 3.3 x 10 ~ (-3) degrees at room temperature for use as a Peltier coolers capable of reaching a maximum temperature difference of 78 ° C at room temperature when used as a single-stage pair. In addition, six Peltier coolers made from these ternary alloys allow for a continuous temperature drop from 300K to 159K. The thermoelectric properties of these alloys are so superior that they can be explained by their lower lattice thermal conductivity, small temperature dependence, and increased bandgap with Sb 2 Se 3.