本實驗成功利用氣相沉積法合成出一維ZnS奈米結構，其中zinc blende及wurtzite兩相是共存的，接著在不同條件下進行以ZnS當作模板，由CuCl2提供Cu來源，在管型爐中利用陽離子交換法將ZnS轉換成Cu2-xS。利用掃描式電子顯微鏡(SEM)觀察一維奈米結構的表面形貌，X光繞射分析來鑑定相結構，穿透式電子顯微鏡(TEM)探討奈米材料的微結構及成長機制。
　　在300℃反應時，原本是wurtzite結構的ZnS，經過陽離子交換反應轉換為rhombohedral結構的Cu1.8S，並具有一維超晶格。rhombohedral結構的Cu1.8S是meta-stable相，在短時間(5min)的反應中可觀察到，但是將反應時間拉長(15min)後，會再轉變成cubic結構的Cu1.8S，若反應前就是zinc blende結構ZnS，陽離子交換反應後會直接轉換成為cubic結構的Cu1.8S，且具有三維超晶格，這些超晶格是因為Cu1.8S中的大量Cu空缺規則(ordered)排列所造成，這裡將提出超晶格結構的原子模型，也可以發現經過陽離子交換反應後材料的尺寸、形貌及結構會被保存下來。當反應溫度提高至400℃、500℃，可以得到Cu2S的monoclinic及hexagonal結構。根據文獻Cu1.8S材料具有良好的導電性，加上超晶格結構可以阻擾聲子的移動而降低導熱性，因此是個很有潛力的熱電材料。

This study is focused on solid state phase transformation of ZnS to synthesize one-dimensional Cu2-xS nanostructures by using two-step vapor deposition process. One-dimensional ZnS nanostructures are first synthesized using ZnS powders as the source, followed by the growth of Cu2-xS nanostructures through cation exchange reactions using CuCl2 as the source at different temperature. The X-ray diffraction patterns show the presence of Cu1.8S and Cu2S under different conditions. The microstructure and defects of the Cu2-xS nanostructures are analyzed using transmission electron microscopy. At 300℃,the product is meta-stable rhombohedral Cu1.8S with 1-D superlattices and stacking faults. By prolonging the reaction time, the rhombohedral Cu1.8S would transform to cubic Cu1.8S with 3-D superlattices accompanied by zigzag morphology, pores and twins due to stress release. All the superlattices are caused by the ordered arrangement of copper vacancies. We find that while the reactions are controlled by kinetics at 300℃, they are controlled by thermodynamics at higher temperatures. Owing to good electric conductivity and superlattice-induced poor thermal conductivity, Cu1.8S could be a potential thermoelectric material.

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