以放電紡絲法探討製程參數如基板加熱，與前驅溶液中高分子種類和重量，與Zn摻雜對CuAlO2奈米線生長之影響。結果顯示基板加熱可以加速紡絲纖維的水分揮發及附著，促進CuAlO2奈米線之生長。而前驅溶液中PVA(分子量：88000-98000)重量超過1g時會促進CuO相生長。在本實驗中，紡絲纖維經空氣中1100℃退火後可得到100〜200 nm的純相CuAlO2奈米線。Zn摻雜會促進CuO相生長。添加Zn=1.5%、在氬氣氣氛中退火溫度達1150℃，可抑制CuO相生長。若添加Zn超過1.5%、在空氣中冷卻或者溫度未達1150℃則CuO相會生成。TEM/EDS分析結果顯示CuAlO2與Zn摻雜CuAlO2奈米線多為多晶結構，且奈米線中Cu和Al的分布不均。
經由紫外光光譜量測，CuAlO2與Zn摻雜CuAlO2奈米線其直接能隙分別為3.4、3.93、4.7eV與3.44、3.92、4.72eV，此現象可能與奈米線中Cu和Al的分布不均有關。

The effects of processing parameters such as substrate heating, the kind and weight of polymer in the precursor solution, and Zn doping on the growth of CuAlO2 nanowires (NWs) by electrospinning were explored. The results showed that the substrate heating at 80℃ can enhance the adherence of as-formed fibers and the evaporation of water therein and thus improve the subsequent growth of CuAlO2 NWs at 1100℃. The weight of PVA polymer in the precursor solution above 1.5 g enhanced the formation of CuO in CuAlO2 NWs. In the present study, pure CuAlO2 NWs with 100-200 nm in size could be synthesized by heating the fibers at 1100℃ in air. Zn doping also enhanced the formation of CuO in CuAlO2 NWs. For the fibers electrospined from the precursor solution with 1.5% Zn, annealing at 1150℃ in Ar could suppressed the formation of CuO in Zn-doped CuAlO2 NWs. From TEM/EDS analyses, most CuAlO2 and Zn-doped CuAlO2 NWs were polysrystalline and the distribution of Cu and Al elements in them was inhomogeneous.
From the UV-vis. spectra, the direct bandgaps of CuAlO2 and Zn-doped CuAlO2 NWs were measured to be 3.4, 3.93, 4.7eV and 3.44, 3.92, 4.72eV, respectively. This result may be explained in terms of the inhomogeneous distribution of Cu and Al elements in them.

[1] R. D. M., "CRC Handbook of Thermoelectrics", CRC Press, Boca Raton, USA (1995).
[2] G. S. Nolas, J. W. Sharp, H. J., "Goldsmid,Thermoelectrics: Basic Principles and New Materials Developments", Springer-Verlag, Heidelberg (2001).
[3] K. Park, K. Ko, W. Seo, "Thermoelectric properties of CuAlO2", Journal of the European Ceramic Society,250, 2219-2222 (2005).
[4] 張立德, 張玉剛, "一維納米材料中的新效應和新功能功", 功能材料2004年增刊,350,
[5] M. Dresselhaus, G. Dresselhaus, X. Sun, Z. Zhang, S. Cronin, T. Koga, "Low-dimensional thermoelectric materials", Physics of the Solid State,410, 679-682 (1999).
[6] J. Heremans, C. Thrush, D. Morelli, "Thermopower enhancement in lead telluride nanostructures", Physical Review B,700, (2004).
[7] J. Heremans, C. Thrush, D. Morelli, M.-C. Wu, "Thermoelectric Power of Bismuth Nanocomposites", Physical Review Letters,880, (2002).
[8] R. Venkatasubramanian, E. Siivola, T. Colpitts, B. O'Quinn, "Thin-film thermoelectric devices with high room-temperature figures of merit", Nature,4130, 597-602 (2001).
[9] T. Ishiguro, A. Kitazawa, N. Mizutani, M. Kato, "Single-crystal growth and crystal structure refinement of CuAlO2", Journal of Solid State Chemistry,400, 170-174 (1981).
[10] K. Koumoto, H. Koduka, W.-S. Seo, "Thermoelectric properties of single crystal CuAlO2 with a layered structure", Journal of Materials Chemistry,110, 251-252 (2001).
[11] T. J. Seebeck, "Magnetic polarization of metals and minerals", Abhandlungen der Deutschen Akademie Wissenschaften zu Berlin,2650, (1823).
[12] T. J. Seebeck, "Methode, Platinatiegel auf ihr chemische reinheit durck thermomagnetismus zu prufen", Schweigger's J. Phy.,460, 101 (1826).
[13] J. C. A. Peltier, "Nouvelles experiences sur la caloricite des courants electrique", Ann. Chim. Phys,560, 371 (1834).
[14] W. Thomson, "An account of Carnot`s theory of the motive power of heat", Proc. R. Soc. Edinburgh,160, 541 (1849).
[15] W. Thomson, "On a Mechanical Theory of Thermo-Electric Currents", Proceeding Of The Royal Society Of Edinburgh,910, (1851).
[16] W. Thomson, "Account of researches in thermo-electricity", Philos. Mag.,50, 62 (1854).
[17] W. Thomson, "On the electrodynamic qualities of metals", Philos. Trans. R. Soc. London,1460, 649 (1856).
[18] F. Roeser, "Thermoelectric Thermometry", Appl. Phys.,110, 388 (1940).
[19] P. W. Bridgeman, "The Thermodynamics of Electrical Phenomena in Metals", Dover, New York (1961).
[20] H. B. Callen, "Application of Onsager's Reciprocal Relations to Thermoelectric, Thermomagnetic and Galvanomagnetic Effects", Phys. Rev.,13490, (1948).
[21] H. B. Callen, "Irreversible thermodynamics of thermoelectricity", Rev. Mod. Phys.,260, 237 (1954).
[22] D. M. Rowe, "Thermoelectrics Handbook: Micro to Nano", CRC Press, New York (2006).
[23] S. i. Yanagiya, N. Van Nong, J. Xu, N. Pryds, "The Effect of (Ag, Ni, Zn)-Addition on the Thermoelectric Properties of Copper Aluminate", Materials,30, 318-328 (2010).
[24] I. Terasaki, Y. Sasago, K. Uchinokura, "Large thermoelectric power in NaCo2O4 single crystals", Physical Review B,560, R12685 (1997).
[25] A. Georges, G. Kotliar, W. Krauth, M. J. Rozenberg, "Dynamical mean-field theory of strongly correlated fermion systems and the limit of infinite dimensions", Reviews of Modern Physics,680, 13 (1996).
[26] G. Palsson, G. Kotliar, "Thermoelectric Response Near the Density Driven Mott Transition", Physical Review Letters,800, 4775 (1998).
[27] Y. Ando, N. Miyamoto, K. Segawa, T. Kawata, I. Terasaki, "Specific-heat evidence for strong electron correlations in the thermoelectric material (Na,Ca)Co2O4", Physical Review B,600, 10580 (1999).
[28] K. Takahata, Y. Iguchi, D. Tanaka, T. Itoh, I. Terasaki, "Low thermal conductivity of the layered oxide (Na,Ca)Co2O4: Another example of a phonon glass and an electron crystal", Physical Review B,610, 12551 (2000).
[29] M. Ohtaki, T. Tsubota, K. Eguchi, H. Arai, "High-temperature thermoelectric properties of (Zn1-xAlx)O", Journal of Applied Physics,790, 1816-1818 (1996).
[30] K. Uehara, J. S. Tse, "Calculations of transport properties with the linearized augmented plane-wave method", Physical Review B,610, 1639 (2000).
[31] K. Kishimoto, M. Tsukamoto, T. Koyanagi, "Temperature dependence of the Seebeck coefficient and the potential barrier scattering of n-type PbTe films prepared on heated glass substrates by rf sputtering", Journal of Applied Physics,920, 5331 (2002).
[32] Y.-M. Lin, M. S. Dresselhaus, "Thermoelectric properties of superlattice nanowires", Physical Review B,680, 075304 (2003).
[33] F. A. Benko, F. P. Koffyberg, "Opto-electronic properties of CuAlO2", Journal of Physics and Chemistry of Solids,450, 57-59 (1984).
[34] M. V. Lalic, J. Mestnik-Filho, A. W. Carbonari, R. N. Saxena, "Changes induced by the presence of Zn or Ni impurity at Cu sites in CuAlO2 delafossite", Solid State Communications,1250, 175-178 (2003).
[35] M. S. Lee, T. Y. Kim, D. Kim, "Anisotropic electrical conductivity of delafossite-type CuAlO2 laminar crystal", Applied Physics Letters,790, 2028 (2001).
[36] H. Kawazoe, M. Yasukawa, H. Hyodo, M. Kurita, H. Yanagi, H. Hosono, "P-type electrical conduction in transparent thin films of CuAlO2", Nature,3890, 939-942 (1997).
[37] P. Poopanya, A. Yangthaisong, C. Rattanapun, A. Wichainchai, "Theoretical Study of Electronic Structure and Thermoelectric Properties of Doped CuAlO2", Journal of Electronic Materials,400, 987-991 (2011).
[38] K. Park, K. Y. Ko, W. S. Seo, "Effect of partial substitution of Ca for Al on the microstructure and high-temperature thermoelectric properties of CuAlO2", Materials Science and Engineering: B,1290, 1-7 (2006).
[39] T. Kurotori, S. Sugihara, "Thermoelectric Properties of CuAl1-xMxO2 (M=Zn, Ca)", MATERIALS TRANSACTIONS,460, 1462-1465 (2005).
[40] K. Park, K. Ko, H. Kwon, S. Nahm, "Improvement in thermoelectric properties of CuAlO2 by adding Fe2O3", Journal of Alloys and Compounds,4370, 1-6 (2007).
[41] N. Tsuboi, Y. Takahashi, S. Kobayashi, H. Shimizu, K. Kato, F. Kaneko, "Delafossite CuAlO2 films prepared by reactive sputtering using Cu and Al targets", Journal of Physics and Chemistry of Solids,640, 1671-1674 (2003).
[42] J. Cai, H. Gong, "The influence of Cu∕Al ratio on properties of chemical-vapor-deposition-grown p-type Cu–Al–O transparent semiconducting films", Journal of Applied Physics,980, 033707 (2005).
[43] S. Zhao, M. Li, X. Liu, G. Han, "Synthesis of CuAlO2 nanofibrous mats by electrospinning", Materials Chemistry and Physics,1160, 615-618 (2009).
[44] Z.-M. Huang, Y. Z. Zhang, M. Kotaki, S. Ramakrishna, "A review on polymer nanofibers by electrospinning and their applications in nanocomposites", Composites Science and Technology,630, 2223-2253 (2003).
[45] G. Taylor, "Electrically Driven Jets", Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences,3130, 453-475 (1969).
[46] D. H. Reneker, I. Chun, "<paper8.pdf>", Nanometre diameter fibres of polymer, produced by electrospinning,70, 216 (1996).
[47] M. M. Bergshoef, G. J. Vancso, "Transparent Nanocomposites with Ultrathin, Electrospun Nylon-4,6 Fiber Reinforcement", Advanced Materials,110, 1362-1365 (1999).
[48] Z. Sun, E. Zussman, A. L. Yarin, J. H. Wendorff, A. Greiner, "Compound Core-Shell Polymer Nanofibers by Co-Electrospinning", Adv. Mater.,150, 22 (2003).
[49] C. J. Buchko, K. M. Kozloff, D. C. Martin, "Surface characterization of porous, biocompatible protein polymer thin films", Biomaterials,220, 1289 (2001).
[50] Holten, "Lactic Acid: Properties and Chemistry of Lactic Acid and Derivatives.", Verlag Chemie., 221 (1971).
[51] X. Zong, K. Kim, D. Fang, S. Ran, B. S. Hsiao, B. Chu, "Structure and process relationship of electrospun bioabsorbable nanofiber membranes", Polymer,430, 4403-4412 (2002).
[52] D. H. Reneker, H. Fong, "Polymer Nanofiber", Inc. American Chemical Society, (2003).
[53] D. K. Kim, S. H. Park, B. C. Kim, B. D. Chin, S. M. Jo, D. Y. Kim, "Electrospun polyacrylonitrile based carbon nanofibers and their hydrogen storages", Macromolecular Research,130, 521-528 (2005).
[54] S. S. Srinivasan, R. Ratnadurai, M. U. Niemann, A. R. Phani, D. Y. Goswami, E. K. Stefanakos, "Reversible hydrogen storage in electrospun polyaniline fibers", International Journal of Hydrogen Energy,350, 225-230 (2010).
[55] Z. Kurban, A. Lovell, S. M. Bennington, D. W. K. Jenkins, K. R. Ryan, M. O. Jones, N. T. Skipper, W. I. F. David, "A Solution Selection Model for Coaxial Electrospinning and Its Application to Nanostructured Hydrogen Storage Materials", The Journal of Physical Chemistry C,1140, 21201-21213 (2010).
[56] R. Chaim, Z. J. Shen, M. Nygren, "Transparent nanocrystalline MgO by rapid and low-temperature spark plasma sintering (Vol 19, pg 2527, 2004)", Journal of Materials Research,190, 3715-3715 (2004).
[57] R. Chaim, "Densification mechanisms in spark plasma sintering of nanocrystalline ceramics", Materials Science and Engineering: A,4430, 25-32 (2007).
[58] M. Tokita, "Trends in Advanced SPS Spark Plasma Sintering Systems and Technology", J. Soc. Pow. Tech. Jap.,300, 790 (1993).
[59] J. E. Garay, S. C. Glade, U. Anselmi-Tamburini, P. Asoka-Kumar, Z. A. Munir, "Electric current enhanced defect mobility in Ni3Ti intermetallics", Applied Physics Letters,850, 573-575 (2004).
[60] M. Omori, "Sintering, consolidation, reaction and crystal growth by the spark plasma system (SPS)", Materials Science and Engineering A,2870, 183-188 (2000).
[61] B. Poudel, Q. Hao, Y. Ma, Y. Lan, A. Minnich, B. Yu, X. Yan, D. Wang, A. Muto, D. Vashaee, X. Chen, J. Liu, M. S. Dresselhaus, G. Chen, Z. Ren, "High-Thermoelectric Performance of Nanostructured Bismuth Antimony Telluride Bulk Alloys", Science,3200, 634-638 (2008).
[62] W. Xie, X. Tang, Y. Yan, Q. Zhang, T. M. Tritt, "Unique nanostructures and enhanced thermoelectric performance of melt-spun BiSbTe alloys", Applied Physics Letters,940, 102111 (2009).
[63] 汪建民等人, "材料分析", 中國材料科學學會, (1998).
[64] R. L. Weiher, R. P. Ley, "Optical Properties of Indium Oxide", Journal of Applied Physics,370, 299-302 (1966).
[65] R. D. Shannon, C. T. Prewitt, "EFFECTIVE IONIC RADII IN OXIDES AND FLUORIDES", Acta Crystallographica Section B-Structural Crystallography and Crystal Chemistry,B 250, 925-& (1969).
[66] D. Aston, D. Payne, A. Green, R. Egdell, D. Law, J. Guo, P. Glans, T. Learmonth, K. Smith, "High-resolution x-ray spectroscopic study of the electronic structure of the prototypical p-type transparent conducting oxide CuAlO2", Physical Review B,720, (2005).
[67] Y. Kumekawa, M. Hirai, Y. Kobayashi, S. Endoh, E. Oikawa, T. Hashimoto, "Evaluation of thermodynamic and kinetic stability of CuAlO2 and CuGaO2", Journal of Thermal Analysis and Calorimetry,990, 57-63 (2010).
[68] H. Yanagi, S.-i. Inoue, K. Ueda, H. Kawazoe, H. Hosono, N. Hamada, "Electronic structure and optoelectronic properties of transparent p-type conducting CuAlO2", Journal of Applied Physics,880, 4159-4163 (2000).
[69] W. Lan, W. Cao, M. Zhang, X. Liu, Y. Wang, E. Xie, H. Yan, "Annealing effect on the structural, optical, and electrical properties of CuAlO2 films deposited by magnetron sputtering", Journal of Materials Science,440, 1594-1599 (2009).
[70] J. Cai, H. Gong, "The influence of Cu/Al ratio on properties of chemical-vapor-deposition-grown p-type Cu--Al--O transparent semiconducting films", Journal of Applied Physics,980, 033707 (2005).
[71] A. N. Banerjee, K. K. Chattopadhyay, "Size-dependent optical properties of sputter-deposited nanocrystalline p-type transparent CuAlO2 thin films", Journal of Applied Physics,970, 084308 (2005).
[72] G. Li, X. Zhu, H. Lei, H. Jiang, W. Song, Z. Yang, J. Dai, Y. Sun, X. Pan, S. Dai, "Preparation and characterization of CuAlO2 transparent thin films prepared by chemical solution deposition method", Journal of Sol-Gel Science and Technology,530, 641-646 (2010).
[73] M. S. Lee, T. Y. Kim, D. Kim, "Anisotropic electrical conductivity of delafossite-type CuAlO2 laminar crystal", Applied Physics Letters,790, 2028-2030 (2001).
[74] W. D. Kingery, H. K. Bowen, D. R. Uhlmann, "Introduction to Ceramics(2nd ed.)", John Wiley & Sons, New York, 519 (1976).
[75] A. N. Banerjee, R. Maity, P. K. Ghosh, K. K. Chattopadhyay, "Thermoelectric properties and electrical characteristics of sputter-deposited p-CuAlO2 thin films", Thin Solid Films,4740, 261-266 (2005).