本論文之目的是在多孔矽上堆疊氧化鋅，藉由結合多孔矽與氧化鋅兩種發光材料，以研製出能發白光的機構。
多孔矽以陽極蝕刻法生成，基材為n型矽晶片，當氫氟酸濃度在12%，照度維持2.5 mW/cm2，電流密度首先使用115 mA/cm2蝕刻1 min之後，緊接著調降電流密度到30 mA/cm2蝕刻30 min，實驗結果發現可以得到最大的光致發光強度，其波峯位置在波長680 nm處。
為避免多孔矽發光受高溫影響，所以氧化鋅以化學沉澱法生成，使用莫耳濃度1M硝酸鋅溶液，氨水為沉澱劑，反應形成不同的前驅物Zn(OH)2或[Zn(NH3)4]2+再塗佈於矽基材上，溫度150℃時間6小時進行熱分解，光致發光(PL)量測結果發現以Zn(OH)2與[Zn(NH3)4]2+生成之氧化鋅波峯位置分別位於波長502 nm及 481 nm。
多孔矽與氧化鋅堆疊之後的光致發光(PL)量測，顯示發光區域涵蓋全可見光區400 nm ~ 750 nm，用紫外光照射可直接觀察到發白光情形。

Abstract

The goal of this study is to synthesize materials which emit white light. Porous silicon and zinc oxide are selected as luminescent materials.
We first prepare porous silicon as substrate. Porous silicon is formed from anodization etching of a n-type Si wafer in 12% HF with a current density of 30 mA/cm2 for 30min. The porous silicon can be found to have high PL intensity centered around 680 nm.
Zinc oxide coatings are prepared by precipitation method using the solution of 1M Zn(NO3)2 and NH4OH. The precursor solution forms transitional phases of Zn(OH)2 or [Zn(NH3)4]2+ then transformed to zinc oxide after heating it at 150℃ for 6 hr. The zinc oxide coatings from pyrolysis of Zn(OH)2 or [Zn(NH3)4]2+ emit light at 502 nm and 481 nm, respectively.
Stacks of ZnO and porous Si are fabricated for white light emission. The result of PL measurement shows all visible light bands are covered.

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