Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/3978
標題: 短週期超晶格緩衝層對GaN/InGaN P-N接面 光電壓低頻雜訊之影響
Effects of short-period superlattice buffer on the low-frequency noise of photovoltage for GaN/InGaN P-N junctions
作者: 鄭善允
Cheng, Shan-Yun
關鍵字: short-period superlattice;短週期超晶格;noise;雜訊
出版社: 精密工程學系所
摘要: 
摘要
近年來,因為開發新能源的趨勢,所以太陽能電池和發光二極體成了熱門的研究,太陽能電池是開發新能源,發光二極體是節省能源,光電元件因為其結構微小,其雜訊的大小,也是研究的一大課題。
本論文是研究短週期超晶格緩衝層對GaN/InGaN P-N接面低頻雜訊光電壓的影響。樣品共分三種,分別是做一個短週期超晶格為緩衝層,兩個短週期超晶格緩衝層,三個短週期超晶格緩衝層的P-N接面。在加順向偏壓時,兩個超晶格緩衝層樣品有最大的電流(4V下85mA),在相同的電壓下,發光效率也以兩個超晶格緩衝層樣品最好,而三個超晶格緩衝層樣品因為應力釋放,其缺陷密度反而比兩個超晶格緩衝層和一個超晶格緩衝層樣品高。我們對這些樣品做照光電壓不同的雜訊量測,判斷其雜訊的形式和其照光電壓對雜訊大小之影響,也判斷是否和其缺陷密度大小有關,根據實驗所得的數據可以知道,以含有一個超晶格緩衝層所量得的雜訊最小,兩個超晶格緩衝層樣品次之,三個超晶格緩衝層樣品雜訊最大,和其差排密度大小並不完全吻合,只能說雜訊大者,其差排密度有可能是比較大的,而其雜訊形式均是以1/f為主。

Abstract
In recent years, the trend of developing new energy resources, solar cell and light emitting diode becomes a popular area in research. The solar cell gives a new source of energy, the light emitting diode saves energy for lighting and many other photonic devices provide variety of service for our daily life. The noise behavior of these systems devices is a very important topic while being applied to real systems.
This thesis is about the effect of short-period superlattice (SPSL) in GaN/InGaN P-N junction structures on noise of photo voltage. We used three kinds of samples in this study: samples with a SPSL layer, samples with two buffer layers, and samples with three SPSL layers. Under same forward bias voltage, samples with two buffer layers has the largest current(85mA at 4V) and also luminescence efficiency.Samples with three buffer layers has a larger defect density than that of other samples due to the strain relaxation problem. We measured the noise spectrum of these samples under different photo-voltage bias. The photovoltage of these samples shows an enhanced 1/f noise, whose magnitude increases with the power of illumination. According to our experiment data,the samples with one buffer layer has the lowest noise, while samples with two buffer layers has the second lowest noise and samples with three buffer layers has the highest noise. Even though the defects density and noise behavior do not match completely, our results do suggest that higher dislocation density causes higher noise level.
URI: http://hdl.handle.net/11455/3978
Appears in Collections:精密工程研究所

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