利用VLS機制在多孔矽上面成長氧化鋅奈米線之特性研究

Abstract

我們成功的利用化學傳輸沉積系統經由VLS方法在最佳條件下將氧化鋅奈米線成長在多孔矽基板上。在掃描式電子顯微鏡的影像中，所有成長在多孔矽基板上的奈米線在尺度上比矽基板具有比較好的均勻性，在(002)這個方向也比矽基板上具有較高的方向性。從選區電子繞射圖形以及低溫螢光光譜的量測，氧化鋅奈米線都具有單晶結構以及好的光學性質。在低溫螢光光譜，自由與被施子束縛住的激子輻射強度大於其它的光譜， 當環境溫度增加時，自由激子的輻射強度會逐漸的增加，最後在室溫下其強度最為強。

We have successfully fabricated the ZnO nanowires under the optimum conditions on porous silicon (PS) substrates by vapor-liquid-solid method using chemical vapor transport and condensation system (CVTC). All the nanowires grown on PS showed a better uniformity in dimension and a high orientation in direction (002) than on silicon substrate from SEM images. From selected area electron diffraction(SAED) pattern and low temperature photoluminescence (LT-PL) measurement, ZnO nanowires showed a single crystalline structure and to have a good optical quality. At low temperature photoluminescence (LT-PL), the free and donor-bound exciton lines dominate the spectra, while with increasing temperature emission from free exciton grow rapidly and finally become the dominant line.