現今之主流熱電裝置皆由稀有金屬材料製成，但稀有金屬的高昂價格與來源短缺是為熱電材料發展阻礙的主因。因此本研究以地殼存量第二多的矽與製作成本低廉的有機高分子作為基底熱電研究材料，分別配以性質相似的矽鍺接合減少熱傳導率，磁性附加缺陷的矽奈米線以提高電性，加入推拉電子基的有機導電高分子，進行不同的截面積生長方向、尺寸大小、排列方式的改變，達到熱電優值的提升。本研究希望透過人工摻雜方式，藉由改變熱電材料載子濃度，觀察導電率、席貝克係數和熱傳導率變化，以期能求得不同熱電晶片材料熱電優值的最大值。
熱電材料的轉換效率可由熱電優值(thermoelectric figure of merit, ZT)來決定，而在ZT值中包含了電子傳導率(electrical conductivity)、席貝克係數（Seebeck coefficient）和熱傳導率（thermal conductivity），藉由計算這些參數，將可知道熱電轉換效率的優劣。本研究從第一原理開始，使用密度泛函理論（density functional theory, DFT）為主要理論，配以Kohn-Sham方程式、平面波基底(plane wave basis)、贗勢(pseudopotential)及廣義梯度近似（generalized gradient approximation, GGA）方法，模擬計算出能帶結構(band structure)、能量態密度（density of state, DOS），再以密度泛函微擾理論(density functional perturbation theory, DFPT)計算出聲子頻散圖(phonon dispersion relation)、聲子態密度(phonon density of state)。得到以上之數據後，將能量態密度帶入一維波茲曼傳輸方程式(Boltzmann transport equation)求得材料之電導率、席貝克係數與電子熱傳導率。聲子群速度則由聲子頻散圖中對頻率作微分求得，再帶入公式求得熱傳導率。研究結論為矽鍺超晶格能有效降低聲子速度使熱傳導率下降，而缺陷矽奈米線能夠藉由磁性的附加增加相同自旋量的電子躍遷至導帶的機率，提高其電子傳導率，最後附加推拉電子基的理想有機導電高分子奈米線能有機會提升熱電因子，大量提高其熱電優值至ZT 4。

1. Vining, C.B., Semiconductors are cool. Nature, 2001. 413(6856): p. 577-578.
2. Rowe, D.M., CRC handbook of thermoelectrics. 1995, Boca Raton, FL: CRC Press. 701 p.
3. Liu, W.S., Yan, X., Chen, G., and Ren, Z.F., Recent advances in thermoelectric nanocomposites. Nano Energy, 2012. 1(1): p. 42-56.
4. Berger, L.R. and Berger, J.A., Countermeasures to Microbiofouling in Simulated Ocean Thermal-Energy Conversion Heat-Exchangers with Surface and Deep Ocean Waters in Hawaii. Applied and Environmental Microbiology, 1986. 51(6): p. 1186-1198.
5. Dresselhaus, M.S., Chen, G., Tang, M.Y., Yang, R.G., Lee, H., Wang, D.Z., Ren, Z.F., Fleurial, J.P., and Gogna, P., New directions for low-dimensional thermoelectric materials. Advanced Materials, 2007. 19(8): p. 1043-1053.
6. Snyder, G.J. and Toberer, E.S., Complex thermoelectric materials. Nature Materials, 2008. 7(2): p. 105-114.
7. Chen, Z.G., Han, G., Yang, L., Cheng, L.N., and Zou, J., Nanostructured thermoelectric materials: Current research and future challenge. Progress in Natural Science-Materials International, 2012. 22(6): p. 535-549.
8. Martin-Gonzalez, M., Caballero-Calero, O., and Diaz-Chao, P., Nanoengineering thermoelectrics for 21st century: Energy harvesting and other trends in the field. Renewable & Sustainable Energy Reviews, 2013. 24: p. 288-305.
9. Vineis, C.J., Shakouri, A., Majumdar, A., and Kanatzidis, M.G., Nanostructured Thermoelectrics: Big Efficiency Gains from Small Features. Advanced Materials, 2010. 22(36): p. 3970-3980.
10. Han, M.K., Ahn, K., Kim, H., Rhyee, J.S., and Kim, S.J., Formation of Cu nanoparticles in layered Bi2Te3 and their effect on ZT enhancement. Journal of Materials Chemistry, 2011. 21(30): p. 11365-11370.
11. Hicks, L.D. and Dresselhaus, M.S., Effect of Quantum-Well Structures on the Thermoelectric Figure of Merit. Physical Review B, 1993. 47(19): p. 12727-12731.
12. Hicks, L.D. and Dresselhaus, M.S., Thermoelectric Figure of Merit of a One-Dimensional Conductor. Physical Review B, 1993. 47(24): p. 16631-16634.
13. Hicks, L.D., Harman, T.C., Sun, X., and Dresselhaus, M.S., Experimental study of the effect of quantum-well structures on the thermoelectric figure of merit. Physical Review B, 1996. 53(16): p. 10493-10496.
14. Hochbaum, A.I., Chen, R.K., Delgado, R.D., Liang, W.J., Garnett, E.C., Najarian, M., Majumdar, A., and Yang, P.D., Enhanced thermoelectric performance of rough silicon nanowires. Nature, 2008. 451(7175): p. 163-U5.
15. Boukai, A.I., Bunimovich, Y., Tahir-Kheli, J., Yu, J.K., Goddard, W.A., and Heath, J.R., Silicon nanowires as efficient thermoelectric materials. Nature, 2008. 451(7175): p. 168-171.
16. Steele, M.C. and Rosi, F.D., Thermal Conductivity and Thermoelectric Power of Germanium-Silicon Alloys. Journal of Applied Physics, 1958. 29(11): p. 1517-1520.
17. Abeles, B., Beers, D.S., Dismukes, J.P., and Cody, G.D., Thermal Conductivity of Ge-Si Alloys at High Temperatures. Physical Review, 1962. 125(1): p. 44-&.
18. Slack, G.A. and Hussain, M.A., The Maximum Possible Conversion Efficiency of Silicon-Germanium Thermoelectric Generators. Journal of Applied Physics, 1991. 70(5): p. 2694-2718.
19. Zhu, G.H., Lee, H., Lan, Y.C., Wang, X.W., Joshi, G., Wang, D.Z., Yang, J., Vashaee, D., Guilbert, H., Pillitteri, A., Dresselhaus, M.S., Chen, G., and Ren, Z.F., Increased Phonon Scattering by Nanograins and Point Defects in Nanostructured Silicon with a Low Concentration of Germanium. Physical Review Letters, 2009. 102(19).
20. Shirakawa, H., Louis, E.J., Macdiarmid, A.G., Chiang, C.K., and Heeger, A.J., Synthesis of Electrically Conducting Organic Polymers - Halogen Derivatives of Polyacetylene, (Ch)X. Journal of the Chemical Society-Chemical Communications, 1977(16): p. 578-580.
21. Yan, H., Ohno, N., and Toshima, N., Low thermal conductivities of undoped and various protonic acid-doped polyaniline films. Chemistry Letters, 2000(4): p. 392-393.
22. Kirchmeyer, S. and Reuter, K., Scientific importance, properties and growing applications of poly( 3,4-ethylenedioxythiophene). Journal of Materials Chemistry, 2005. 15(21): p. 2077-2088.
23. Ouyang, B.Y., Chi, C.W., Chen, F.C., Xi, Q.F., and Yang, Y., High-conductivity poly (3,4-ethylenedioxythiophene): poly(styrene sulfonate) film and its application in polymer optoelectronic devices. Advanced Functional Materials, 2005. 15(2): p. 203-208.
24. Jiang Feng-Xing, X.J.-K., Lu Bao-Yang1, Xie Yu, Huang Rong-Jin and Li Lai-Feng, Thermoelectric Performance of Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate). IOP Science, 2008.
25. Touloukian, Y.S., Thermal conductivity: metallic elements and alloys. Thermophysical properties of matter, v 1. 1970, New York,: IFI/Plenum. xxvii, 53a, 1469, A46 p.
26. Levine, I.N., Quantum chemistry. 6. ed. 2009, Upper Saddle River, N.J.: Pearson Education. 2 bd.
27. Segall, M.D., Lindan, P.J.D., Probert, M.J., Pickard, C.J., Hasnip, P.J., Clark, S.J., and Payne, M.C., First-principles simulation: ideas, illustrations and the CASTEP code. Journal of Physics-Condensed Matter, 2002. 14(11): p. 2717-2744.
28. Hohenberg, P. and Kohn, W., Inhomogeneous Electron Gas. Physical Review B, 1964. 136(3B): p. B864-&.
29. Kohn, W. and Sham, L.J., Self-Consistent Equations Including Exchange and Correlation Effects. Physical Review, 1965. 140(4A): p. 1133-&.
30. Payne, M.C., Teter, M.P., Allan, D.C., Arias, T.A., and Joannopoulos, J.D., Iterative Minimization Techniques for Abinitio Total-Energy Calculations - Molecular-Dynamics and Conjugate Gradients. Reviews of Modern Physics, 1992. 64(4): p. 1045-1097.
31. Vanderbilt, D., Soft Self-Consistent Pseudopotentials in a Generalized Eigenvalue Formalism. Physical Review B, 1990. 41(11): p. 7892-7895.
32. Baroni, S., de Gironcoli, S., Dal Corso, A., and Giannozzi, P., Phonons and related crystal properties from density-functional perturbation theory. Reviews of Modern Physics, 2001. 73(2): p. 515-562.
33. 歐祖銘(洪哲文指導), 固態物理與電聲子動態研究磁化矽奈米線熱電晶片. 國立清華大學動力機械, 2012.
34. 李敏瑋(洪哲文指導), 有機導電高分子熱電晶片之熱電優值固態物理探討. 國立清華大學動力機械系, 2013.
35. Perdew, J.P., Burke, K., and Ernzerhof, M., Generalized gradient approximation made simple. Physical Review Letters, 1996. 77(18): p. 3865-3868.
36. Serway, R.A., Principles of physics. 2nd ed. Saunders golden sunburst series. 1998, Fort Worth: Saunders College Pub. xxxii, 954 p.
37. Fulkerso.W, Moore, J.P., Williams, R.K., Graves, R.S., and Mcelroy, D.L., Thermal Conductivity Electrical Resistivity and Seebeck Coefficient of Silicon from 100 to 1300 Degree K. Physical Review, 1968. 167(3): p. 765-&.
38. Yue, R.R. and Xu, J.K., Poly(3,4-ethylenedioxythiophene) as promising organic thermoelectric materials: A mini-review. Synthetic Metals, 2012. 162(11-12): p. 912-917.
39. Taggart, D.K., Yang, Y.G., Kung, S.C., McIntire, T.M., and Penner, R.M., Enhanced Thermoelectric Metrics in Ultra-long Electrodeposited PEDOT Nanowires (vol 11, pg 125, 2011). Nano Letters, 2011. 11(5): p. 2192-2193.
40. Chang, K.C., Jeng, M.S., Yang, C.C., Chou, Y.W., Wu, S.K., Thomas, M.A., and Peng, Y.C., The Thermoelectric Performance of Poly(3,4-ethylenedi oxythiophene)/Poly(4-styrenesulfonate) Thin Films. Journal of Electronic Materials, 2009. 38(7): p. 1182-1188.
41. Jiang, F.X., Xu, J.K., Lu, B.Y., Xie, Y., Huang, R.J., and Li, L.F., Thermoelectric performance of poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate). Chinese Physics Letters, 2008. 25(6): p. 2202-2205.
42. Bubnova, O., Khan, Z.U., Malti, A., Braun, S., Fahlman, M., Berggren, M., and Crispin, X., Optimization of the thermoelectric figure of merit in the conducting polymer poly(3,4-ethylenedioxythiophene). Nature Materials, 2011. 10(6): p. 429-433.
43. Xie, W.J., He, J., Kang, H.J., Tang, X.F., Zhu, S., Laver, M., Wang, S.Y., Copley, J.R.D., Brown, C.M., Zhang, Q.J., and Tritt, T.M., Identifying the Specific Nanostructures Responsible for the High Thermoelectric Performance of (Bi,Sb)(2)Te-3 Nanocomposites. Nano Letters, 2010. 10(9): p. 3283-3289.
44. Wang, X.W., Lee, H., Lan, Y.C., Zhu, G.H., Joshi, G., Wang, D.Z., Yang, J., Muto, A.J., Tang, M.Y., Klatsky, J., Song, S., Dresselhaus, M.S., Chen, G., and Ren, Z.F., Enhanced thermoelectric figure of merit in nanostructured n-type silicon germanium bulk alloy. Applied Physics Letters, 2008. 93(19).