| 研究生: |
李素昀 Su-Yun Lee |
|---|---|
| 論文名稱: |
驅動電壓調控奈米複合材料的電傳導特性 Electrically controlled transport characteristics in nanoparticle compacts |
| 指導教授: |
李文献
Wen-Hsien Li |
| 口試委員: | |
| 學位類別: |
碩士 Master |
| 系所名稱: |
理學院 - 物理學系 Department of Physics |
| 畢業學年度: | 94 |
| 語文別: | 中文 |
| 論文頁數: | 63 |
| 中文關鍵詞: | 奈米複合材料 、奈米壓合材料 、奈米材料的電傳導特性 、穿透率與電阻率 |
| 外文關鍵詞: | tunneling transport probability, electric transport, tunneling transport, nanocompact, nanoparticle |
| 相關次數: | 點閱:14 下載:0 |
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本實驗採用Ag與Cu/Cu2O兩種奈米微粒依各種不同質量比例調配後均勻混合,壓合製作成(Ag)x(Cu/Cu2O)100-x奈米複合樣品,其中x=0、15、20、25、30、35、50、65及100。另外亦採用粒徑為2.2 nm的Au奈米微粒製作成的(Au) -68% 奈米複合樣品,探討(Ag)x(Cu/Cu2O)100-x以及(Au) -68% 奈米複合材料的電子傳輸機制。
我們利用電子穿隧模型來解釋電子的傳輸機制,在(Au) -68% 與(Ag)20(Cu/Cu2O)80-42% 樣品中,分別給予不同電流流經樣品,顯示出穿隧位壘會隨溫度上升而增加,電阻率經一轉折溫度Tm,樣品從金屬性行為轉變為類絕緣性行為,轉折溫度Tm隨著電流I的增加而上升,電阻率大小與驅動電壓(即提供電子的能量)有關。
以固定量測時所提供的驅動電壓量測(Ag)20(Cu/Cu2O)80-42% 樣品,觀察到電阻率經一轉折溫度Tm,樣品從金屬性行為轉變為類絕緣性行為,轉折溫度Tm隨著電壓V的增加而上升,顯示出量測時所提供的驅動電壓可調控電阻率的大小,此為穿隧傳導的自然特性。
The nanoparticle compacts were fabricated by evenly mixing 2.4 nm Ag and 4.8 nm core/shell Cu/Cu2O nanoparticles with selective mass ratios. The nanocompacts of x/100-x mass ratio for Ag/(Cu/Cu2O) was donated as (Ag)x(Cu/Cu2O)100-x. Its relative mass density with respect to the bulk material would be used to denote the compacting density (CD). An (Au)100-68% nanocompact was also be fabricated by 2.2 nm Au nanoparticles. The resistivities of the nanocompacts were measured by the standard four-probe setup, operated in the constant current or constant voltage mode.
The resistivities of nanocompacts may be described by tunneling transport. For nanocompacts consist of ultra small nanoparticles, the resistivities growing indicate that tunneling barrier potentials increase as the temperature was raised. In addition, the resistivities were also found to be very sensitive to the bias voltage.
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