一維II-VI族半導體奈米材料其形貌、自組裝與異質接面之合成及特性研究

Abstract

於奈米材料領域中，除零維奈米粒子（亦被稱為量子點）外，具有不同長寬比，且維度均在奈米尺度下之一維半導體奈米晶體亦受到大家的重視，原因在於這類一維奈米棒的光學以及電子特性均受到粒徑大小以及不同形狀的影響。在本論文中，於溶液態的環境下反應，可以在不外加方向控制手段的前提下合成大小為二平方微米之自組裝硫化鎘陣列。奈米棒的濃度、硫化鎘本身特性以及界面活性劑上的碳鍊均對自組裝陣列之形成有決定性的影響。另外，藉由控制介面活性劑之種類與反應溫度，可合成長寬比最大達到三百之硫化鎘奈米線。最後，引入金屬奈米粒子當作保護基，合成出軸向異質結構之鉑-硒化鎘-硫化鎘奈米棒。本論文之結果應可應用於設計及構築複雜性的異質奈米結構。

Besides zero dimensional semiconducting nanoparticles (also referred to as “quantum dots”), one dimensional semiconducting nanocrystals with dimensions in the range of nanometer and with different aspect ratios have also drawn much attention due to their fascinating size- and shape-dependent optical and electronic properties. In this study, by using a solution-based method, CdS self-bundled arrays with an area of as large as 2.0 μm2 could be produced in the absence of an external direction-controlling process. Matching in nanorod concentration, intrinsic properties of CdS, and the hydrocarbon chains of the surfactants between adjacent CdS rods play key roles in the self-assembly. Also, the self-bundled CdS nanorods exhibit optical emission nearly free from the defect-states. In addition, by optimizing the use of surfactants and temperature, the aspect ratio of CdS nanowires with diameter of 3.5 nm can be tuned up to 300. Finally, by applying metallic nanoparticles as a protecting group, nanorods with axial heterojunctions could be obtained with a mechanism different from that of the SLS model. Results of this study could serve as basic concepts in nanocrystal architecture.