臺灣博碩士論文加值系統

本實驗分成兩部分：研究樣品的發光機制以及時間解析激發探測量測系統
第一部分我們藉由量測不同溫度下激發強度與發光強度的關係，可以判斷發光機制是自由載子或是激子所主宰。如過去文獻所預期，在室溫下發光機制主要來自自由載子：當溫度降低時，激子的影響逐漸變大。
第二部分我們建立一套時間解析量測系統來研究量子點樣品的生命期。為了驗證此方法的可行性。我們選擇樣品發光波長落在時間相關單光子計數器系統可量測範圍，並藉由量測到的載子生命期與我們所建立的時間解析量測系統相比後，可以得到一致的結果。在驗證了此量測系統後，我們針對四種不同量子點樣品進行量測載子生命期。接著利用此量測系統研究變溫下的量子點載子生命期，發現量子點載子生命期隨溫度上升先變長再變短。

In this thesis, we have established a time-resolved system for measuring the carrier lifetimes of quantum dots.
Firstly, we have studied the recombination mechanism of quantum dots by using the excitation power dependent photoluminescence measurement. It has been demonstrated that the free-carrier recombination is the dominant mechanism at room temperature. The influence of exciton becomes larger when the temperature is decreased.
Then, in order to verify this time-resolved system, a time- correlated single photon counting (TCSPC) system has been established. By comparing the result obtained by TCSPC system, the validity of our time-resolved system is confirmed.
Furthermore, we investigated the temperature dependent carrier lifetimes. It has been shown that the carrier lifetime first increases and then decreases with increasing temperature.

誌謝 i
摘要 ii
ABSTRACT iii
章節 iv
圖目錄 vi
表目錄 xiii
第一章 緒論 1
第一節 半導體雷射簡介 1
第二節 研究動機 4
第三節 論文架構 5
第二章 實驗理論 6
第一節 光激發螢光(Photoluminescence) 6
第二節excitation dependent integrated photoluminescence[9-10] 7
第三節 時間解析激發-探測量測方法(time-resolved pump-probe measurement)理論 9
第四節 時間相關單光子計數系統(Time-correlated single photon counting system：TCSPC)[11] 10
第五節 p-doping和intrinsic樣品的差異 12
第六節 spacer對樣品的影響 12
第三章 元件製作及實驗量測架構 14
第一節 磊晶材料與結構 14
第二節 實驗量測架構 16
2.1 時間解析激發-探測量測方法(time-resolved pump-probe measurement) 16
2.2 時間相關單光子計數系統(Time-correlated single photon counting system：TCSPC) 18
第四章 實驗結果與討論 19
第一節 C系列樣品變溫量測Excitation dependent integrated PL部分： 19
第二節 時間解析激發-探測量測方法與TCSPC時間常數測試：(這部份感謝蘇立杰學長提供協助) 42
第三節C系列樣品變溫時間解析激發-探測量測方法量測 48
第五章 總結 53
參考文獻 55

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