The Optical Characteristics of Surface Plasmons and its Application in Quantum Dot Infrared Photodetector

本文在理論及實驗上計算並量測出在週期排列的金屬銀孔洞上其表面電漿子的能帶圖，且觀察在銀薄膜上以六角形陣列排列之週期孔洞的異常穿透現象。另外，藉由入射光角度的變化，測量出沿不同對稱軸下(ΓM或ΓK方向)之能帶圖。除此之外，我們也觀察孔洞大小的變化對穿透圖形的影響。最後，我們把週期排列金屬銀孔洞陣列應用於量子點紅外線偵測器背面作為濾波器，在寬頻響應中選擇出特定之波段如3-5微米及8-12微米。The band diagram of surface plasmons (SPs) on a periodic array of metal holes is investigated in both theory and experiment. The extraordinary transmission through a silver film perforated with hexagonally ordered holes arrays on Si and GaAs substrates is measured. In addition, the transmission is also measured with increasing angle of incidence so that the energy dispersion relations are obtained along the symmetry axis ΓM or ΓK. Furthermore, the influence of the hole size and shape on the transmission spectra are investigated. Finally, the silver film perforated with periodic hole array is fabricated at the back of the QDIP as a filter to select a specific waveband, i.e., 3-5 μm or 8-12 μm, from a broad photodetector response..Contents Chapter 1 Introduction 01 Chapter 2 The Fundamentals of surface plasmons and infrared detectors 5 2.1 The fundamentals of surface plasmons 5 2.1.1 Surface plasmons on smooth surfaces 5 2.1.2 Surface plasmons on the surface with hole arrays 11 2.2 The fundamentals of QDIP 15 2.2.1 Infrared detectors 15 2.2.2 Quantum dot infrared photodetectors 18 2.3 Process flow 20 2.3.1 Fabrication processes of metal hole arrays 20 2.3.2 Fabrication processes of QDIP 21 2.4 Measuring systems 27 2.4.1 Introduction of FTIR 27 2.4.2 Relative spectral response 28 2.4.3 Absolute responsivity 30 Chapter 3 Extraordinary transmission through a silver film perforated with hexagonally ordered holes arrays 35 3.1 Band diagram of SPs on hexagonally ordered holes arrays 35 3.1.1 Theory 35 3.1.2 Experiments 39 3.1.3 Results and Discussion 42 3.2 Influence of hole size on SPs on periodic metal holes arrays 50 3.2.1 Experiments 50 3.2.2 Results and Discussion 51 Chapter 4 Quantum dot infrared photodetector with periodic metal holes 56 4.1 The characteristic of a separate optical filter cooperated to QDIP 56 4.1.1 Experiments 56 4.2.2 Results and Discussion 58 4.2 The characteristic of extraordinary transmission resulted from SPs integrated to QDIP 64 4.2.1 Experiments 64 4.2.2 Results and Discussion 66 4.3 The influence of surface plasmons (SPs) on the light and dark current of QDIPs 80 Chapter 5 Conclusions 89 Bibliography 9