摻硒化鋅微晶玻璃薄膜之變溫螢光和拉曼斯特散射研究

Abstract

我們利用變溫拉曼光譜和變溫螢光光譜來分析摻硒化鋅微晶玻璃薄膜的特性。從變溫拉曼光譜上，我們可以看出當溫度升高時，光學聲子會衰減到低能量聲子，使得聲子的生命期變短，頻寬變寬。在螢光光譜裡，我們可觀察到當溫度升高時，自由電子─電洞復合和自由電子─受子復合的螢光峰值會往低能量移動，伴隨著螢光強度會減弱，前者乃因半導體的能隙會隨溫度而變，後者則是由於在升溫過程中因熱擾動變大而使載子從自由能態的最低點跨越活化能而跑到非發光能態。

Temperature dependent photolummescence and Raman spectroscopy were used to analyze the properties of ZnSe doped glass thin films. From the temperature dependent Raman spectra, the phonon lifetime and spectra width decrease at high temperature because of the decay of optical phonons into low energy phonons. From the temperature dependent photolum-inescence, we observed the peaks shift to the lower energy and decrease in intensity with increasing temperature related to the transition of free electron-hole and free electron-acceptor. The former is due to change of the energy gaps of semiconductors with temperature, the latter is due to the thermal quenching process that characterizes by the activation energy induces the carrier transition from the potential minimum of the free state to the nonradiative potential.