藉由溶液 -固體 -固體法催化單源先驅物合成硫化鋅及鎘奈米線

Abstract

本研究以「溶液-固體-固體」法於低溫下，藉由固態硫化銀催化溶液態之單源先驅物，再以一步法反應優化並生長出II-VI 族之硫化鋅及硫化鎘半導體奈米線。我們以Zn(DDTC)2 及Cd(DDTC)2 等多硫錯合物鹽類，於100-200℃下引入銀源，除同步生長出硫化銀觸媒粒子及II-VI 族奈米線，並以紫外-可見光吸收光譜、粉末X 光繞射、穿透式電子顯微鏡、X 光吸收光譜等技術，觀察隨反應時間之奈米線生長情況。同時，利用兩相近大小之平面晶格距離，於不同半導體間以磊晶方式生長出硫化鎘-硫化鋅之異質奈米線結構，並測量其導電性之變化。這類II-VI 族半導體奈米線，於溶液中亦可使用中孔洞薄膜材料來限制固態觸媒大小，進而生長出具有方向性之半導體奈米線，以應用在能源轉換之奈米線元件上。

Here we rationally synthesize ZnS and CdS nanowires using single-sourceprecursors via solution-solid-solid (SSS) mechanism in a facile one-step synthesis. Sulfur-rich salt complexes, such as Zn(DDTC)2 and Cd(DDTC)2 were decomposed at 100-200 oC in oleylamine to grow silver sulfide catalysts and subsequently zinc/cadmium sulfide nanowires after an introduction of silver sources into the solution. The nanowires were characterized with UV-vis, PXRD, TEM/HRTEM and EXAFS techniques to reveal the growth mechanisms of the nanowires. Interfaces between CdS-ZnS hetero-semiconductor nanowires are realized by HRTEM and XRD, suggesting epitaxy growth from their close d-spacing in two adjacent semiconductors. Furthermore, we demonstrate growth of oriented nanowires from mesoporous thin film substrates, utilized to energy conversion devices with such oriented semiconductors.