• 作者： 陳永芳; 朱立寰; 潘善中; 剡永聖; 張毅敏; 張鼎張; 張俊彥
• 作者服務機構： 國立台灣大學物理學系; 國立交通大學電子工程學系
• 中文摘要： 本研究報告一些在矽化錯與矽量子井內的有趣現象。光螢光能量與強度表現出不尋常的溫度變化。當溫度增加時，能量先增加後減小；光強度展出類非晶半導體之特性；同時隨激發光強度之增加，光螢光能量會有藍位移現象。持續性光電導可以明顯的觀測到，光電導之衰退符合扭曲指數函數之描述，而光電導之建立遵循一拋物函數。第一階的縱向聲子頻譜呈現不對稱變寬之行為。所有這些觀測到的現象，都能用合金成分的起伏來解釋。因此我們的結果建立了矽化鍺薄膜存在有合金成分的起伏，同時提供合金位能起伏如何影響了材料特性的證據。
• 英文摘要： We report several interesting observations in the study of the optical properties of strained(方程式無法摘錄) quantum wells. Both the photoluminescence energy and intensity showed anomalous tem-perature behavior: The energy first increased, and then decreased with increasing temperature; the intensityshowed a temperature dependence similar to that of amorphous semiconductors and disordered superlattices;and blue shifting of the photoluminescence energy with increasing excitation intensity was observed.Persistent photoconductivity was detected, and the kinetics of its decay and transient buildup followeda stretched-exponential function and a parabolic time dependence, respectively. The first-order longi-tudinal-optical Si-like phonon mode showed asymmetric broadening behavior. All these observations canbe explained by alloy potential fluctuations in a consistent way. Thus, our results firmly establish theexistence of compositional fluctuations in Sil_xGex epilayers and provide evidence showing that alloypotential fluctuations can greatly influence the properties of materials.
• 中文關鍵字： alloy potential fluctuations; Si1-xGex/Si quantum wells
• 英文關鍵字： --