透明導電氧化物(transparent conductive oxides, TCOs)，例如氧化錫(SnO2)、氧化銦(In2O3)、氧化鎘(CdO)和氧化鋅(ZnO)在近幾十年來在光電材料應用的重要性越來越顯著。為了增加這些材料的導電性，我們通常會摻雜入適當的元素來增加其導電載子濃度進而提昇材料的導電度。
在透明導電氧化物的範疇中，氧化銦錫(tin-doped indium oxide, ITO)最常被研究與工業上的應用。然而，氧化銦錫材料暴露在有氧的高溫(>300℃)環境中，其導電度會因為材料中的氧空缺的減少而大幅度的下降。氟摻雜氧化錫(fluorine-doped tin oxide, FTO)比氧化銦錫有更佳的熱穩定性，且在材料價錢上更具有競爭力，因此，氟摻雜氧化錫材料是做為取代氧化銦錫材料的最佳選擇。
隨著元件的尺寸越來越小，透明導電氧化物奈米材料的發展極具有潛力，並且，目前為止並沒有任何單晶氟摻雜氧化錫奈米線的研究。本實驗率先利用熱蒸鍍法成長氧化錫奈米線和氟摻雜氧化錫奈米線，接著使用各種分析儀器TEM、SEM、XRD、EDS量測合成之奈米線的定性和定量分析。之後使用TEM-STM電性量測系統分別測量單根氧化錫奈米線和氟摻雜氧化錫奈米線的電性並討論之。
我們可以確定合成的氧化錫奈米線和氟摻雜氧化錫奈米線皆為成長方向[100]的單晶。此外，從TEM-STM系統量測到單根氟摻雜氧化錫奈米線的電阻率確實遠小於單根氧化錫奈米線，氟的摻雜的確對此材料的電性有顯著的影響。

Transparent conductive oxides (TCO) ,such as SnO2, In2O3, CdO, and ZnO, have become increasingly important in a large variety of applications due to demands for optically-transparent, conductive materials.[1-2] To enhance the conductivity, we usually dope suitable atoms introduce more free carriers.[3] It has been widely used as electric leads in optoelectronic devices such as flat panel displays and thin film solar energy cells.

A common TCO used in research and industry is tin-doped indium oxide (ITO). However, ITO experiences a reduction of electrical conductivity when exposed to oxygen at elevated temperatures (> 300 ℃). Therefore, FTO, which is much more thermally stable, is often used as an alternative to ITO. As device size continues to decrease, the potential use of nanoscaled structures of these TCOs grows. However, very little to no work has been published regarding the fabrication of FTO nanowires.[4]

The authors report the growth of F-doped SnO2 single crystalline nanowires by carrying out the thermal evaporation of solid Sn and SnF2 powders a in an Ar/O2 ambient gas. We analyzed the samples with scanning electron microscopy, X-ray diffraction, transmission electron microscopy. From the EDS spectra, we can quantify fluorine-doping in the nanowires is about 2 at%. The electrical properties of rutile-type F-doped SnO2 low-dimensional structures were analysed using a scanning tunnelling microscopy (STM) in situ holder for transmission electron microscopes (TEM).The measured I-V curve obtained typically show Ohmic-like behavior between the gold electrode and F-doped SnO2 nanowires. And the resistivity of FTO NWs is 0.0278Ω-cm, much smaller than pure SnO2 NWs(289 Ω-cm).

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