完整后设资料纪录
DC 栏位 | 值 | 语言 |
---|---|---|
dc.contributor.author | 柯克宪 | en_US |
dc.contributor.author | 陈军华 | en_US |
dc.date.accessioned | 2015-11-26T01:07:08Z | - |
dc.date.available | 2015-11-26T01:07:08Z | - |
dc.date.issued | 2012 | en_US |
dc.identifier.uri | http://140.113.39.130/cdrfb3/record/nctu/#GT079918573 | en_US |
dc.identifier.uri | http://hdl.handle.net/11536/49666 | - |
dc.description.abstract | 热电材料之奈米化工程已被理论及实验上证明,确实能有效提升材料热电优值(Figure of merit, ZT定义为σS2T /κ)。热电材料奈米化后,生成之表面或介面能大幅度降低热传导系数(κ),同时因为奈米尺寸引发之量子局限(Quantum confinement)效应,将有机会同步提升功率因子(σS2),从而达到提升热电优值的目标。相较于已被广泛研究之碲化铋(Bi2Te3)块材,硒化锑(Sb2Se3)块材本身具有更高之Seebeck系数(1800 μVK-1)与较低热传导系数(~1 Wm-1K-1),故被视为继碲化铋后,另一个极具发展潜力之常温型热电材料系统。然而,至目前为止,硒化锑奈米结构之热电相关报导仍属少数。因此,硒化锑奈米结构之成长,成为一个非常具吸引力及重要之研究主题,藉此可望能达到潜在优异之热电优值。 本研究成功利用脉冲雷射沉积技术,于不使用模板与触媒的前提下,于SiO2/Si基板上,制备一系列有序组装硒化锑低维度奈米结构,其组成单元之形貌多样,包括奈米齿状、奈米翅状、奈米柱状、奈米板状、奈米镊状及奈米管状等一、二维奈米结构。其中除了奈米柱状结构为非晶结构之外,其余皆为高品质单晶结构。另发现此些奈米结构有序组装而成之薄膜,皆具有特殊之结晶优选方位。利用结构区带模型(Structure-zone model, SZM) 与自我触媒辅助气-液-固 (Vapor-liquid-solid, VLS)之成长机制可分别合理解释低温(<300 oC)连续性与高温(>300 oC)不连续性奈米有序组装薄膜之成长。在变温导电率 (20‒400 oC)量测方面,发现硒化锑奈米翅状薄膜具有极佳之导电率(20‒750 Sm-1),趋近文献所提单根奈米线之值(852 Sm-1)。另外,在室温下,奈米齿状结构薄膜之导电率(~1.54 Scm-1)较多晶薄膜高4‒5个数量级,表示成功的改善硒化锑导电率。 | zh_TW |
dc.description.abstract | Nanostructure engineering been theoretically and experimentally proven as a practial strategy for thermoelectric materialshas for effectively enhancing thermoelectric figure of merits, ZTs (defined as σS2T /κ). By nanostructuring, not only could the largely created surface or interfaces inhibit the thermal conductivity (κ), but the power factor (σS2) could be improved through the induced quantum confinement. Antimony selenide (Sb2Se3) has a higher Seebeck coefficient (1800 μVK-1) and lower thermal conductivity (~2.7 Wm-1K-1) compared with the widely studied bismuth telluride (Bi2Te3) bulk and is thus considered as a promising alternate of the room-temperature thermoelectric materials for the next generation. However, to date, thermoelectric data realted to the Sb2Se3 nanostructures have less been reported. Therefore, growth of nanostructured Sb2Se3 becomes a very attractive and important research topic for approaching potentially outstanding thermoelectric performance. In this work, by using pulsed laser deposition (PLD) techniques, a series of well-aligned nanostructured Sb2Se3 films was successfully prepared on insulated SiO2/Si substrates without prebuilt catalysts and templates. At least seven types of previously unreported Sb2Se3 nanostructures including nanoteeth, nanowings, nanorods, nanodecks, nanotweezers, nanocolumns, and nanotubes were reproducibly obtained via precisely controlling the substrate temperature and ambient pressures. The temperature-dependent growth seems to be reasonably explained by the well-known structure zone model (SZM) and self-catalyst enhanced vapor-liquid-solid (VLS) growth. Among these specimens, the Sb2Se3 nanowings show an excellent electrical conductivity of 750 Sm-1 at 400 oC, which is comparable to the reported value of an isolated nanowire (852 Sm-1). In addition, the room-temperature electrical conductivity of the Sb2Se3 nanoteeths is 4 to 5 orders higher that that of the non-nanostructured Sb2Se3 film. In this work we succeded in improving the electrical conductivity of Sb2Se3 film. | en_US |
dc.language.iso | zh_TW | en_US |
dc.subject | 热电 | zh_TW |
dc.subject | 自组装 | zh_TW |
dc.subject | 薄膜 | zh_TW |
dc.subject | 脉冲雷射沉积 | zh_TW |
dc.subject | thermoelectric | en_US |
dc.subject | self-assembling | en_US |
dc.subject | thin-film | en_US |
dc.subject | pulsed laser deposition | en_US |
dc.title | 脉冲雷射沉积有序组装硒化锑低维度奈米结构于热电转换之应用 | zh_TW |
dc.title | Pulsed laser deposition of orientedly-assembled low-dimensional Sb2Se3 nanostructures for thermoelectric applications | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | 材料科学与工程学系 | zh_TW |
显示于类别: | Thesis |
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