量子點雷射二極體之特性研究與應用

Abstract

本論文主要在研究砷化銦量子點雷射二極體的性質與應用。量子點雷射二極體中，載子捕捉受限制的聲子瓶頸效應，對於其作為光電元件的影響很大。為了獲得更多微觀的載子動力學資訊，本論文探討量子點變溫條件下的電激發光增益頻譜，載子捕捉與聲子瓶頸造成的非平衡態費米狄拉克分布等現象，可獲得Auger載子復合與電子－聲子散射率等微觀資訊。經由曲線擬合，可證實砷化銦量子點中非放射性復合主因為LA聲子，載子捕捉為LO聲子且聲子瓶頸對增益頻譜的光子增益尖峰值有明顯影響，量子點中的載子散射較塊材明顯受限等等結論。 為了描述量子點中尺寸分布對頻譜造成的影響，一般普遍採用'能量'上的高斯函數加以處理，此章根據前人實驗結果，提出對'尺寸'的高斯函數來處理增益計算，以達到更好的曲線擬合效果 另外本論文也替相異雙重量子井與量子點雷射二極體的高速直接調變進行純理論模擬，探討雙重量子井與量子點中的直接調變。

The thesis is focused on the investigation on the characteristics and applications of InAs quantum-dot laser diodes. In quantum-dot laser diodes, carrier capture that is limited by phonon bottleneck effect has significant influence on the application of electro-optical devices. In order to obtain more microscopic information about carrier dynamics, in this thesis, many phenomena are explored such as the electro-luminescence spectrum at variant temperatures, carrier capture, phonon bottleneck and consequential non-equilibrium Fermi-Dirac distribution. The above phenomena can give us microscopic information such as Auger recombination and electron-phonon scattering. By curve fitting, the main reason of nonradiative recombination can be proved as electron-LA phonon scattering, and carrier capture as electron-LO phonon scattering which has evident influence to optical gain spectrum in InAs quantum dot. In quantum dots, carrier scattering is much more limited than in bulk. In order to model the influence of size distribution to gain spectrum, “energy” distribution Gaussian functions are usually adopted. According to the experimental events, “size” Gaussian distribution functions are proposed to achieve better fittings. Furthermore, the simulations of high speed modulation in nonidentical quantum wells and quantum dot laser diodes are also available in this thesis.