介孔二氧化矽的光致發光應用引起相當廣泛的注意，其發光機制為介孔二氧化矽有高比表面積可提供大量的缺陷中心，能藉由表面改質，就可以改變發光強度與波長。本研究以溶膠-凝膠法製作介孔二氧化矽薄膜，以TEOS為反應前驅物，利用界面活性劑CTAB作為合成介孔結構之模板，以旋轉塗佈的方式將溶液塗佈於矽基板上形成前驅物薄膜，經煆燒400 oC持溫時間12 h，利用ICP-CVD進行H2電漿表面處理，藉以改變表面缺陷與化學鍵結，並以同步輻射光激發試片，進一步解析PL特性。以四氯化鍺加入合成介孔二氧化矽溶液中，同樣以旋轉塗佈形成薄膜前驅物，煆燒400 oC持溫時間12 h後，並以PECVD進行H2電漿表面處理。為進一步分析摻雜鍺二氧化矽的影響，將摻雜不同鍺莫耳比的介孔二氧化矽粉末進行不同氫氣氛比例還原熱處理600 oC持溫時間5h後，以SEM、TEM、TG-DTA、氮氣等溫吸附/脫附分析、FTIR、XPS與 PL進行分析與探討。
實驗結果顯示，由TEM觀察介孔二氧化矽薄膜經400 oC煆燒後的介孔孔徑尺寸約為1~2 nm，為一連通孔徑的介孔材料，由氮氣等溫吸附/脫附分析得知其擁有高比面積為1144 m2/g，平均孔徑2 nm。PL結果顯示，其具有三個發射光波峰分別為322、387及410 nm，起因分別為非橋氧電洞中心、氫氧基中心、二折疊配位矽中心。在薄膜經過ICP-CVD氫電漿處理後，其322nm (3.85eV)的UV發射光波峰消失，為非橋氧鍵結的氧原子與電漿中解離的氫自由基結合所致。
TEM結果顯示當摻雜Ge/Si莫耳比例為0.01時，薄膜具有連通之孔洞結構，其孔徑尺寸大小一致約為1~2 nm，由氮氣等溫吸附/脫附分析得知其仍具有高比表面積為907 m2/g，平均孔徑為3 nm。摻雜Ge進入薄膜將取代部分的Si形成Ge-O鍵結，PECVD H2電漿表面處理增加薄膜的氧空缺濃度，進而提升PL發光強度。然而，當摻雜Ge/Si莫耳比例> 0.01時，並不會提升PL發光強度，因Ge-O鍵結逐漸聚集並析出造成相分離所導致。
以摻雜Ge/Si莫耳比例為0.2之介孔二氧化矽粉末進行不同還原氣氛比例熱處理，隨著氫氣比例的增加至33.3 %，粉末內二氧化鍺完全還原成金屬鍺。在氫氣還原比例為5 %時，有最高的672 nm (1.84 eV)紅光發光強度，隨著氫氣還原比例的增加，其紅光發光強度逐漸降低。以摻雜不同Ge/Si莫耳比例介孔二氧化矽粉末，氫氣比例固定為5 %進行還原熱處理，摻雜鍺比例為0.05時，其TEM擇區繞射結果顯示立方結構金屬鍺與六方結構的二氧化鍺兩相共存，二氧化鍺的奈米晶粒尺寸為5~8 nm。在摻雜鍺莫耳比例為0.01時，波長位於672 nm (1.84 eV)有最高的紅光發光強度，同時發現波長位於524 nm (2.37 eV)有最高的綠光發光強度，其綠光缺陷能階為二氧化矽本質缺陷Si-H造成。

Visible and ultraviolet luminescence of mesoporous silica for optoelectronic applications has attracted much attention recently. The mechanism of photoluminescence of mesoporous silica arises from a lot of surface defects due to its high specific surface area. If the amount or kinds of defects can be controlled, the intensity and wavelength of PL will be adjusted. Nanostructured mesoporous silica and Ge-doped mesoporous silica thin films have been deposited on silicon substrate by the spin-coating technique using CTAB as a template and GeCl4 as Ge precursor and then calcined at 400 oC for 12 h. The PL behavior of mesoporous silica thin film is related to the defects, ICP-CVD hydrogen plasma was used to modify the chemical bonding on the surface of thin film. Ge-doped mesoporous silica thin film was passivated by PECVD hydrogen plasma. To further study, various molar ratio of Ge/Si were doped in mesoporous silica powder and reduced at 600 oC 5h in different ratio of H2/N2. TG-DTA, XPS, SEM, HRTEM, N2 adsorption-desorption isotherm, FTIR and synchrotron high flux beamline were used to characterize the microstructure and photoluminescence properties of the resulting film.
After calcined at 400 oC for 12 h, from TEM results, the thin film exhibited a very smooth surface and interconnected pores, with a pore size of about 1-2 nm. From N2 adsorption-desorption isotherm results, the specific surface area is up to 1144 m2/g and the average pore size is 2 nm. The synchrotron photoluminescence spectra show that the samples after calcination have three obvious luminescence peaks around 322, 387 and 410 nm arising from nonbridging oxygen hole centers (NBOHCs), twofold-coordinated silicon centers, and Si-OH surface complexes. The UV emission (322 nm) due to NBOHCs is inhibited by H2 plasma treatment, indicating that the nonbridging oxygen was saturated by the hydrogen atoms.
The TEM results suggest that the Ge-doped mesoporous silica thin film with Ge/Si molar ratio of 0.01 was observed a very smooth surface and interconnected pores, with a pore size of about 1-2 nm. From N2 adsorption-desorption isotherm results, the sample with the specific area up to 907 m2/g and the average pore size up to 3 nm could be obtained. In this study, Ge-doped mesoporous silica thin film in which some Si atoms were replaced by Ge atoms according to the X-ray photoelectron spectroscopy analyses. The PL intensity of mesoporous silica passivated by PECVD hydrogen plasma could be increased by germanium-induced oxygen-related defects, but for the samples with Ge/Si molar ratios larger than 0.01, the PL intensity decreased due to the phase separation of germanium oxide.
With increasing the ratio of H2 atmosphere up to 33.3%, the Ge-doped mesoporous silica powder with Ge/Si molar ratio of 0.2 reduced at 600 oC for 5 h, hexagonal GeO2 was reduced into cubic Ge phase. When reduced in 5 % H2, Ge-doped mesoporous silica was characterized by the strongest PL intensity with 672 nm. To further study, 5 % H2 atmosphere was chosen to reduce different molar ratio of Ge-doped mesoporous silica. The Ge-doped mesoporous silica with Ge/Si molar ratio of 0.01 was characterized by the strongest PL intensity peak centered at 672 nm and 524 nm.

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