二六族半導體奈米晶體的製備、鑑定及應用

Fabrication, Characterization, and Application of II-VI Semiconductor Nanocrystals

王筱芳(Hsiao-Fang Wang)

指導教授 ： 董瑞安

國立清華大學/原子科學院/生醫工程與環境科學系/碩士(2008年)

摘要

中文摘要

本研究的目的是在找尋一個低毒性的半導體奈米晶體用以替代含鎘的材料。在本研究中，我們將內容分為三個部份。第一部分是合成與鑑定硒化鎘╱硫化鋅核殼的半導體奈米晶體。在這個部分，我們建立了一套成熟的系統，成功地合成粒徑大小從3.6 nm到6.9 nm及發光波長560 nm到610 nm的半導體核殼結構。利用吸收光譜推算其能隙大小介於2.09-2.28 eV，輔以電子顯微鏡用來觀察粒徑的表面型態跟大小。為了確定其核殼結構的存在，我們以電子探測微分析儀（EPMA）及電子能量損失光譜儀（EELS）鑑定結構中元素的分布，證實其核殼結構的存在。化學定量部份，以X射線能量散佈分析儀（EDS）做半定量，再以感應耦合電漿原子發射光譜分析儀（ICP-AES）做定量，因為前者為表面鑑定，測得的殼層結構元素相較之下較多。第二部份是合成與鑑定不含鎘的半導體替代材料，成功地合成出wurtzite的硒化鋅量子點。另外，由於摻雜過渡金屬不易，我們試圖去找到一些合理的原因去解釋這個現象。最後，我們設計了一個發光二極體（LED）的結構，並將我們合成出來的量子點材料利用旋轉塗佈在發光層中，探討其發光特性與轉換效率，發現效率與發光層的表面覆蓋率有相當大的關係。

關鍵字

二六族半導體

並列摘要

Abstract

The purpose of this study was to fabricate less toxic semiconductor nanocrystals to replace the serious toxic cadmium-containing materials. In this study, we divided the content into three parts. The first part was the fabrication and characterization of CdSe/ZnS core/shell semiconductor nanocrystals. In this part, we established a system, successfully synthesized the semiconductor core/shell structure, the diameters are from 3.6 nm to 6.9 nm and emission wavelengths are from 560 nm to 610 nm. Then, the calculated energy gaps were from 2.09 to 2.28 eV by using the absorption spectra, and using TEM to observe the morphology and confirm the particle size. To make sure the existence of core/shell, we used EPMA and EELS to confirm the distribution of element in this structure. In stoichiometry, we used EDS and ICP-AES to make quantification, the former is more easily to detect the element of shell due to it is a surface analysis method. The second part was the fabrication and characterization of the alternative materials, non-cadmium containing semiconductor nanocrystals, and we succeeded in synthesizing the wurtzite-ZnSe QDs. In addition, due to the difficulties of doping transition metals, we tried to find some reasonable reasons to explain the phenomenon. Finally, we designed a LED device by using spin-coating to discuss the emissive character and efficiency and found that the emissive efficiency was greatly related the surface coverage of emissive layer.

並列關鍵字

HASH(0x1c87a1e0)

參考文獻

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