氮化鎵奈米線和不同三甲基銦處理時間氮化銦鎵發光二極體之光電特性 = In...
國立高雄大學應用物理學系碩士班

 

  • 氮化鎵奈米線和不同三甲基銦處理時間氮化銦鎵發光二極體之光電特性 = Investigations of the Electro-optical Properties of GaN Nanowires and InGaN LEDs with Different TMIn Treatment Times
  • 紀錄類型: 書目-語言資料,印刷品 : 單行本
    並列題名: Investigations of the Electro-optical Properties of GaN Nanowires and InGaN LEDs with Different TMIn Treatment Times
    作者: 林士凱,
    其他團體作者: 國立高雄大學
    出版地: [高雄市]
    出版者: 撰者;
    出版年: 2009[民98]
    面頁冊數: 143面圖、表 : 30公分;
    標題: 催化劑尺寸影
    標題: Anisotropic Strain of GaN Nanowire
    電子資源: http://handle.ncl.edu.tw/11296/ndltd/70632483333242579963
    附註: 參考書目:面
    附註: 指導教授:馮世維
    摘要註: 此論文由兩個部分構成:第一部分是應變氮化鎵奈米線的光電特性研究;另一部分是三甲基銦處理對氮化銦鎵/氮化鎵p-i-n磊晶片和發光二極體元件的光學和材料特性影響。 在第一個部份,氮化鎵奈米線使用金屬鎵蒸氣與氨蒸氣直接反應在氮化鎵微凸平台基板,利用橫向增長沿著m-軸 成長,四個氮化鎵奈米線樣品隨著不同氨氣流量(20, 40, 60 與 80每分鐘標準毫升)被成長。除了樣品80每分鐘標準毫升氨氣流量之外, m軸奈米線的強度在c面平台表面隨著氨氣流量增加而增加。陰極發光影像的發光型態預期與奈米線奈米結構有關。樣品40與60每分鐘標準毫升氨氣流量的樣品顯示,密度較高的氮化鎵奈米線導致陰極發光影像呈現一個較高對比和較強強度。另外,氨氣流量愈高,平面應變 和 輕微地減少,這表示在較高氨氣流量樣品中,一個較小的壓縮應變沿著奈米線成長方向和一個較小的伸張應變沿著半徑方向。此外,各向異性的平面應變會影響光學特性和奈米線的外型分佈。極化光激螢光結果顯示,較高氨氣流量樣品的極化程度較低。並且,在較高氨氣流量的樣品中,一個較小的壓縮應變沿著奈米線成長方向,導致較長的長度,使得一個較小的直徑被觀察到。 在第二個部份,我們研究氮化銦鎵/氮化鎵p-i-n磊晶片與發光二極體元件,隨著不同三甲基銦處理時間的光學與材料特性。實驗結果顯示,三甲基銦處理能提高氮化銦鎵/氮化鎵多重量子井磊晶內部量子效率與增強發光。經過三甲基銦處理後,觀察到樣品中氮化銦鎵中的銦聚集被抑制,相位較純,銦成分較均勻,缺陷強度較小,與較好的量子井結構。另外,利用三甲基銦處理使p-i-n磊晶顯示較高的銦成分、較強的綠光放射、與較短的衰減時間。此外,我們也準備四個不同三甲基銦處理時間的發光二極體元件,隨著處理時間增加,發光二極體元件顯示較強電激發光強度、較狹窄的電激發光頻譜、較好的發光效率。並且,從時間解析電激螢光結果顯示,經過180秒三甲基銦處理過的樣品,其較短的反應時間表示較好的量子井結構有幫助載子鬆弛,同時較好的量子井結構也有助於載子結合。 從應用的觀點,我們的研究結果對固態照明有很大的應用潛力,這樣的研究結果也能促進在臺灣發光二極體產業的進展。 This dissertation consists of two parts:one is optical properties of strained GaN nanowires and the other is the effects of TMIn treatment on the optical and material characteristics of InGaN/GaN p-i-n epilayer and LED device. In the first part, we report GaN nanowires through direct reaction of metal gallium vapor with flowing NH3 on GaN mesas substrate. Four GaN nanowires samples grown from ELO stripes along m-axis were prepared with different NH3 flow rates (20, 40, 60 and 80 sccms). Except for the sample 80 NH3, the density of m-axis nanowires on the c-plane mesa surface increases substantially with higher NH3 flow rate. The luminescence pattern in the CL image is expected to correlate with the nanowire nanostructures. The samples 40 and 60 sccm NH3 show a higher density of GaN nanowires such that the CL images present a higher contrast and stronger intensity. In addition, with a higher NH3 flow rate, the in-plane strains and decreases slightly. This implies a smaller compressive strain along wire growth direction and a smaller tensile strain along the radial direction in the highly NH3-flow-rate sample. Furthermore, the anisotropic in-plane strain can impact the optical property as well as shape distribution of nanowires. From the results of polarized PL results, it was found that the higher the NH3 flow rate, the lower the degree of polarization. Also, a smaller compressive strain along wire growth direction in the highly NH3-flow-rate sample results in a longer length such that a smaller diameter was observed. In the second part, the optical and material characteristics of InGaN/GaN p-i-n epilayer and LED device with TMIn treatment were studied. It was shown that TMIn treatment can improve internal quantum efficiency and enhance luminescence of InGaN/GaN MQW epilayers. With TMIn treatment, both InGaN decomposition and indium aggregation are suppressed such that purer phase, more homogeneous indium composition, less defect density, and better quantum well structures were observed. In addition, TMIn treatment makes the p-i-n epilayers show higher indium composition, stronger green emission, and shorter the recombination decay time. Furthermore, four LED devices with different TMIn treatment times were prepared. With a longer treatment time, the LED device shows stronger EL intensity, narrower EL width, better luminescence efficiency. Also, from the TREL results, the shorter responses times of sample TMIn-180 sec suggests that better quantum well structure helps to carrier relaxation. The better quantum well structure in the TMIn-treated sample helps to carrier recombination. From the viewpoint of applications, our investigated results have significant potential application on solid state lighting. They could also promote the progress of the LEDs industry in Taiwan.
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310001861239 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 423203 4442 2009 一般使用(Normal) 在架 0
310001861221 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 423203 4442 2009 c.2 一般使用(Normal) 在架 0
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