元件結構對電注入式微碟雷射特性之影響

Influence of Device Structures on Current-injection Microdisk Laser Characteristics

李易(I LEE)

指導教授 ： 毛明華

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.00337

摘要

本實驗室過去已成功做出直徑6.5微米五層InGaAs量子點主動層的電注入式微碟雷射，並可在室溫下以脈衝模式操作，其閾值電流為0.45mA、特徵溫度為107K。在此篇論文中，我們展示了同樣主動層改變金屬的厚度與柱子向內蝕刻深度的元件，其室溫下閾值電流為0.18mA，特徵溫度則是216K，Q值約為3400。另外，我們也首次嘗試了連續操作，最高溫可到220K，閾值電流為1.8mA。我們分別討論了金屬厚度對微碟雷射操作上的影響，以及實驗數據的驗證。
另外，我們也嘗試改變主動層結構，採用的是三層InAs量子點主動層，其主動層內量子點層間距較大，從10nm增加到35nm。我們分別討論了層間距以及層數減少對載子生命期乃至於閾值電流的影響。而此微碟雷射在主動碟直徑7.8微米時，元件最高可操作至260K，閾值電流為0.48mA，特徵溫度則為195K。

關鍵字

量子點 ； 微碟型 ； 雷射 ； 電注入

並列摘要

Our laboratory has successfully fabricated current-injection microdisk lasers using five-layer InGaAs quantum dots as active medium. They can be operated at 300K in pulsed mode. The threshold current of a 6.5 um diameter microdisk laser is 0.45mA, and the characteristic temperature is 107K. In this thesis, we fabricated microdisk lasers using the same active material but with increased thickness of p-side metal. The threshold current can be further reduced to 0.18mA at 300K, and the characteristic temperature rose to 216K. Quality factor is about 3400. In addition, continuous mode operation was first used and the highest temperature where lasing could still be achieved is 220K with threshold current of 1.8mA. The effect of p-side metal thickness on characteristics of microdisk lasers will be discussed.
Furthermore, we also fabricated microdisk lasers using different active layer. We use three-layer InAs quantum dots as active medium. The thickness of spacer between quantum dot layers is increased from 10nm to 35nm. We also discussed the influence of spacer thickness and number of stacks on carrier lifetime and threshold current. The highest temperature of a 7.8 um microdisk laser from which lasing could still be achieved is 260K with threshold current of 0.48mA, and the characteristic temperature is about 195K.

並列關鍵字

quantum dot ； microdisk ； laser ； current-injection

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