一、二六族化合物半導體奈米粒子其粒徑與雙光子吸收截面積探討
二、二六族化合物半導體奈米材料於聲學聲子性質研究

由於量子限量化效應的影響，奈米材料表現出與塊材不同的特性，諸如材料的光電磁等物理特性，甚至因為在奈米材料其表面積對體積的比值很大，進而影響其化學性質。本篇論文主要分成兩部分，第一部分探討奈米材料的雙光子躍遷的特性。第二部分則探討當空間被侷限的時候。聲學聲子呈現所謂的量子化的效應。論文中的第一章主要是回顧了早期其他的研究群對奈米材料的基礎特性進行探討，因為奈米材料其尺度介在巨觀塊材與分子之間，在探討其能帶結構時需考慮限量化效應的有想，早期理論上探討引入了粒子在一維盒中的模型、有效粒子質量等來解釋奈米材料的電子結構。另外，並舉出奈米材料在光電元件上應用的前瞻性。第二章則是回顧文獻中合成奈米材料的方法，利用膠體化學的方式合成了硒化鎘與硒化碲來應用在第三章雙光子吸收截面積與粒徑關係探討，接著利用膠體化學的方式來合成硒化鎘─硒化碲核─殼奈米材料與硒化鎘，於第四章中進行限量化的聲學聲子探討。另外嘗試用高溫裂解醋酸鋅合成粒徑單一性的氧化鋅奈米顆粒，期望未來能探討兆赫波吸收特性。並於第二章中討論調控不同的界面活性劑比例來進行奈米材料的形狀控制，因為特殊形狀的奈米結構在不同的光電元件有不同的應用性與前景。

關鍵字

量子點；奈米棒；聲學聲子；雙光子吸收；二六族核殼奈米材料

並列摘要

Part 1: The size-dependent two photon absorption (TPA) cross section of II-VI semiconductor quantum dots (QDs) has been investigated. As the size of the QDs increased, the TPA cross section was found to be empirically related via a power-law proportionality of 3.5 and 5.6 to the diameters of CdSe and CdTe QDs. These results can be rationalized by a theoretical model of two-photon excitation in a system incorporating excitons and defects. Part 2: With spatial confinement, low dimensional systems such as QDs and nanowires (NWs) exhibit not only electronic but also acoustic energy quantization. In 1882, Lamb had already studied the acoustic normal modes confined in a homogeneous free sphere. Two types of modes, torsional and spheroidal (SPH), were derived from the stress-free boundary condition on the spherical surface. Taking advantage of the charge separation structure in the CdSe/CdTe core-shell type-II QDs, we experimentally observed and verified the existence the resonance-enhanced dipolar interaction between terahertz (THz) photons and their corresponding eigenmode (l=1). We also observed that the piezoelectricity of CdSe QDs can induced THz photon absorption related to inactive breathing mode (l=0). From our THz absorption spectrum, we found that the corresponding absorption cross section of CdSe/CdTe QDs shows a D4 (D: diameter) dependence, and the frequency of absorbed photons is inversely proportional to D of the QDs and agrees with that of dipolar active mode. The absorption peak of CdSe QDs which related to breathing mode also shows that the frequency of peak is inversely to the D of the CdSe QDs. We can covert the THz photons into a phonon of the same frequency through charge separation of CdSe/CdTe and the piezoelectricity of CdSe.

並列關鍵字

quantum dots ； nanorods ； core/shell structure ； two photon absoptioption ； confined acoustic phonon

參考文獻

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延伸閱讀

Huang, Y. C. (2019). 合成具尺寸控制的二氧化鈰八面體奈米粒子並探討其尺寸效應在光學和電化學上的影響 [master's thesis, National Tsing Hua University]. Airiti Library. https://www.airitilibrary.com/Article/Detail?DocID=U0016-0206202016154137
Lin, Y. C. (2013). 光子晶體奈米洞陣列對發光二極體出光特性之影響 [master's thesis, National Taiwan University]. Airiti Library. https://doi.org/10.6342/NTU.2013.02662
洪韻婷 (2012). 奈米尺度光與物質作用之增益和控制Part 1: 自組裝金奈米粒子表面增益拉曼效應之比較研究Part 2: 電漿奈米電路中模態之轉換 [master's thesis, National Tsing Hua University]. Airiti Library. https://doi.org/10.6843/NTHU.2012.00233
馬瑋聆（2015）。Frabrications of Sb2S3 Quantum Dot and Exfoliated Montmorillonite/Ionic Liquid Composites and their Applications on Dye Sensitized Solar Cells〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU.2015.00904
Jiang, M., Li, Y., Li, S., Zhou, H., Cao, X., Bao, S., Gao, Y., Luo, H., & Jin, P. (2014). Room Temperature Optical Constants and Band Gap Evolution of Phase Pure M_1-VO_2 Thin Films Deposited at Different Oxygen Partial Pressures by Reactive Magnetron Sputtering. Journal of Nanomaterials, 2014(), 453-458-058. https://doi.org/10.1155/2014/183954

國際替代計量

一、二六族化合物半導體奈米粒子其粒徑與雙光子吸收截面積探討二、二六族化合物半導體奈米材料於聲學聲子性質研究

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