我們利用超高時間解析upconversion的實驗方法量測硒化鎘鋅/硒化鋅（Zn0.91Cd0.09Se/ZnSe）多重量子井的動態螢光光譜隨時間的變化。討論其載子冷卻隨井寬的不同和隨晶格溫度（TL）不同而變化的情形。實驗結果顯示載子被405nm（3.07 eV）之雷射激發後，會藉由與LO-phonon作用快速釋放能量。當載子多餘能量漸漸減少至小於LO-phonon的能量時，會改成與acoustic phonon作用的形式慢慢地釋放能量。我們也定義了載子的有效釋放聲子時間（effective phonon emission time, τLO）。並證明在II-VI族和III-V族半導體裡其effective phonon emission time不會隨井寬的變小而改變。且隨晶格溫度（TL）的上升有變小的趨勢。此外，我們也討論了生命期隨波長變化的關係。

The hot carrier dynamics of Zn0.91Cd0.09Se/ZnSe multi-quantum wells were studied using the femtosecond time-resolved photoluminescence upconversion technique. The carrier cooling behavior was investigated for different compositions at various lattice temperatures. The hot carriers generated photoexcitation by 405nm Ti:sapphire laser pulses release their excess energy primarily through carrier-LO-phonon interaction. As the excess energy reduce to the amount that lower than the energy of LO phonon, the excess energy was released by carrier-TA-phonon scattering before radiative recombination occurs. We have determined the scattering times of carrier-LO-phonon scattering at different lattice temperatures. No hot phonon effects was found at low photoexcited carrier density. The dependence of photoluminescence lifetime on wavelength was also discussed.

中文摘要……………………………………………………………………...I
英文摘要……………………………………………………………………..II
第一章 導論…………………………………………………………….1
第二章 熱載子的冷卻機制………………………………………….6
2.1載子釋放能量的過程………………………………………………6
2.2 釋放能量的機制……………………………………………………8
2.3 釋放能量速率（Energy Loss Rate, ELR）理論………………10
2-4 載子在CdSe中不同機制下之ELR比較………………………....15
第三章 樣品說明…………………………………………………19
第四章 實驗裝置及光路說明………………………………………22
4.1 Upconversion簡介…………………………………………22
4.2 實驗裝置……………………………………………………24
4.3 光路說明……………………………………………………25
4.4 其他實驗相關………………………………………………26
第五章 實驗結果與討論……………………………………………29
第六章 結論…………………………………………………………44
參考文獻………………………………………………………………46

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