硒化銦磊晶層和奈米柱之光學特性

Optical properties of gamma-In2Se3 epilayers and nanorods

胡哲豪(CHE-HAO HU)

指導教授 ： 沈志霖

中原大學/理學院/應用物理研究所/碩士(2008年)

https://doi.org/10.6840/cycu200900585

摘要

本文從螢光的分析了解γ-In2Se3磊晶層和奈米柱的熱電子能量鬆弛。在室溫螢光光譜中，發現γ-In2Se3磊晶層和奈米柱結構都有不錯的螢光訊號，表示這些材料可以應用在光電元件中。實驗中利用變溫下不同激發功率之光激螢光光譜及低溫下變電場的光激螢光光譜量測來研究γ-In2Se3的電子溫度。我們以LO聲子散射是熱電子能量鬆弛的主要機制來分析變功率和變電場下的光激螢光，發現電子溫度隨電子功率損失率的實驗結果與理論模擬相當吻合。這表示LO聲子散射確實是熱電子能量鬆弛的主要機制。我們也從事拉曼散射光譜，發現151 cm-1(19 meV)的位置有一拉曼訊號，與熱電子能量鬆弛模擬中的LO聲子能量吻合，驗證了γ-In2Se3的LO聲子能量確為19 meV。此外，實驗中也獲得了γ-In2Se3的聲子生命期，並發現有熱聲子現象。

關鍵字

奈米 ； 硒化銦磊晶層

並列摘要

We investigated energy relaxation of the hot electrons in γ-In2Se3 epilayers and nanorods. The room-temperature photoluminescence (PL) of theγ-In2Se3 epilayers and nanorods can be observed, indicating these materials can be used in the optolectronic devices. The electron temperatures of the hot electrons in γ-In2Se3 epilayers and nanorods were obtained from dependence of the excitation power and applied electric field on PL. A model based on the electron-LO-phonon scattering was used to analyze the electron temperature of hot electrons as a function of inγ-In2Se3 epilayers and nanorods. It was found the measured electron temperatures are in good agreement with the analysis from the above model, demonstrating the dominant scattering process in the energy relaxation is the electron-LO-phonon scattering. In addition, the 151-cm-1 peak observed in the Raman scattering can be related to the LO-phonon mode in γ-In2Se3. The LO-phonon lifetime of the γ-In2Se3epilayers can be obtained, which is higher than the theoretical value. This deviation is attributed to presence of the non-equilibrium hot-phonon effects.

並列關鍵字

nanorods ； gamma-In2Se3

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