- 學位論文
矽材發光之研究與矽奈米結構對光激發光頻譜線寬縮窄之效應
Investigation of the linewidth reduction effect of Photoluminescence spectra from silicon nanostructures
摘要
矽光源儼然已成為現今超大型積體電路中最迫切需要的元件。在未來不論工業上或是科學上都扮演了舉足輕重的角色。本論文由使用矽奈米結構提高矽材發光效率著眼，研究矽奈米結構對矽材發光之實際影響。在研究中發現在矽材表面製作奈米結構，在低溫下將可以使得光激發光頻譜的線寬縮窄。製作不同的矽表面奈米結構，以期在相同溫度下達到更窄的頻譜線寬，以及更明顯的激子侷限凝聚效應。 我們製作不同的矽表面奈米結構，包含矽奈米柱與矽奈米粒子層。這些元件在低溫下測量的光激發光頻譜有明顯的頻譜線寬縮窄效應。經由理論的分析我們認為矽奈米結構的效應在於縮窄頻譜線寬、提高激子散射時間、以及降低連續激子能量範圍。我們或許可以藉由尺寸更小、排列更規則的矽奈米結構來達到在較高溫度下就可使頻寬縮小的目標，以及更強的載子侷限效應使激子凝聚的現象更為顯著。
並列摘要
Silicon light source is the most urgently needed device in the VLSI nowadays, and will play an important role in science and in technology. The aim of this thesis is to research through what mechanism and how the silicon nanostructures affect the luminescence spectra of silicon under low temperature. Nanostructures on silicon are found to contribute to the reduction of the linewidth of its photoluminescence (PL) spectrum under low temperature. We created variant silicon nanostructures on the surface silicon wafer, inclusive of silicon nanopillar structure and silicon nanoparticles layer. The effects of the devices with silicon nanostructures are suspected to the reduct of the linewidth, to increase the relaxation time of excitons and to lower the energy of continuum excitons after theoretical simulation. In addition, excitons are bosons and obey the Bose-Einstein distribution, thus under low temperature and the carrier confinement effects of the nanostructures, mass excitons will concentrate at the lowest energy level. The linewidth reduction effect might take place and the excitons might concentrate at higher temperature under the effects of the silicon nanostructures with more compact sizes and more regular arrangement.