熱電材料是一種可以直接實現熱、電轉化的材料,在能源緊張的今天它具有非常高的研究價值。熱電材料的應用分為制冷和發(fā)電兩個方面,目前制冷已經應用到便攜式冰箱和芯片制冷等方面,發(fā)電已經應用到汽車尾氣系統(tǒng)以及外太空探測電源等方面。就目前的能源現狀而言,傳統(tǒng)能源僅僅能夠維持百余年的能源供應。而我們所利用的傳統(tǒng)能源有三分之二都以廢熱的形式散失掉了,然而熱電材料恰恰可以將散失的熱能進行重新利用。熱電材料百分之十左右的轉換效率雖不及太陽能電池以及核能等新能源的轉換效率高但是它因在新能源材料領域具有穩(wěn)定性好,無噪聲,無污染,體積小,安全可靠等優(yōu)勢而具有廣泛的應用前景。PbTe基熱電材料是傳統(tǒng)的中溫段熱電材料,因為具有良好的電性能和較低的熱導率而備受青睞。鑒于目前學術界對PbTe的研究較為成熟但是制備方法沒有系統(tǒng)研究過,本文主要通過不同的制備工藝對碲化鉛以及鹵族元素摻雜的碲化鉛材料的性能進行優(yōu)化,以尋找最佳的制備工藝,提高材料的性能,并且為其進一步產業(yè)化制備提供科學依據。首先,通過大量的文獻調研發(fā)現n型PbTe材料的性能遠不及p型PbTe熱電材料,所以選取了n型材料作為研究對象,由于鹵族元素和PbTe材料結...

【文章頁數】：95 頁

【學位級別】：碩士

【文章目錄】：
摘要
Abstract
Chapter 1 Introduction
    1.1 Subject Source
    1.2 Background and Significance
        1.2.1 Thermoelectric effect
        1.2.2 Seebeck coefficients
        1.2.3 Electric conductivity
        1.2.4 Thermal conductivity
        1.2.5 Figure of merit
        1.2.6 Conversion efficiency of thermoelectric materials
    1.3 Review of literature
        1.3.1 Room temperature thermoelectric materials
        1.3.2 Middle-temperature range materials
        1.3.3 High-temperature materials
    1.4 Methods of improving performance for thermoelectric materials
        1.4.1 Improving electric conductivity
        1.4.2 Raise Seebeck coefficients under certain conditions
        1.4.3 Decreasing lattice thermal conductivity
    1.5 Applications of thermoelectric materials
    1.6 Research significance and arrangement
Chapter 2 Introduction of the experiment
    2.1 Preparation of samples
        2.1.1 Pure Pb Te
        2.1.2 Preparation of Pb I2 doped samples
        2.1.3 Preparation of halogens elements doped Pb Te
    2.2 Test and characterization
Chapter 3 Investigation of preparation for pure Pb Te
    3.1 Electrical properties of different preparation process
    3.2 Thermal property of different preparation process
    3.3 ZT value of different preparation processes
    3.4 Chapter summary
Chapter 4 Effects of cooling speed on Pb Te1-x Ix
    4.1 Effects of different cooling speed on hand milled Pb Te1-x Ix
        4.1.1 Electric transport properties
        4.1.2 Thermal transport performances
        4.1.3 Figure of merit
        4.1.4 Summary
    4.2 Effects of cooling speed for ball mill Pb Te1-x Ix
        4.2.1 Electrical transport performances
        4.2.2 Thermal transport performances
        4.2.3 Figure of merit
        4.2.4 Summary
    4.3 Effects of cooling speed for ingot PbTe_1-xIx

        4.3.1 Electrical transport properties
        4.3.2 Thermal transport performances
        4.3.3 Figure of merit
        4.3.4 Summary
    4.4 Chapter summary
Chapter 5 Effects of synthesis process on PbTe_1-xI_x

    5.1 Comparisons of ingot, hand mill, ball mill for air cooling Pb Te_1-xI_x

        5.1.1 Electrical transport properties
        5.1.2Thermal transport properties
        5.1.3 Figure of merit
        5.1.4 Summary
    5.2 Comparisons of ingot, hand mill, ball mill for water cooling PbTe_1-xI_x

        5.2.1 Electrical transport properties
        5.2.2 Thermal transport properties
        5.2.3 Figure of merit
        5.2.4 Summary
    5.3 Comparisons of ingot, hand mill, ball mill for furnace cooling PbTe_1-xI_x

        5.3.1 Electrical transport properties
        5.3.2 Thermal transport properties
        5.3.3 Figure of merit
        5.3.4 Research of hand milled and ingot samples under furnace cooling
    5.4 Chapter summary
Chapter 6 Researching for halogen elements doping
    6.1 XRD Characterization
    6.2 Performance of halogens elements doped Pb Te
    6.3 Electrical property
    6.4 Thermal property
    6.5 Chapter summary
Conclusions
References
Acknowledgments



本文編號：3804970

suoshi