本研究利用均一粒徑的二氧化矽粒子在自組裝成光子晶體時,探討改變溼度、濃度與溶劑組成等因子對於晶體結構及光學性質的影響,並且控制環境相對濕度在短時間內得到最佳光性質的光子晶體。均一粒徑之二氧化矽粒子由溶凝膠法所合成出,與溶劑均勻混合後,在密閉箱內控制環境溼度,並採用自然沉降堆積的方式,使樣品溶劑自然揮發,而粒子會自行組裝成規則排列之晶體。 研究結果顯示出在控制環境相對濕度下、溶劑蒸發速率會影響光子晶體的結構與光學性質,同時溶劑的表面張力會影響著晶體結構,而堆積的層數多寡也會影響著光學性質。由自組裝形成光子晶體的機構中,本文提出三階段濕度的形成機制,利用實驗設計法結果得知,最終階段的環境溼度影響來的比第一與第二階段溼度大。最後利用類神經網路法描述三階段溼度與光能隙關係,經由最佳化方法,求得在三階段最佳溼度控制條件下,最短時間內製作出最佳光學性質的光子晶體。
The quality of photonic band gap (PBG) films produced using colloidal silica particles under different sedimentation environments was studied. The fabricating procedure includes particle syntheses, powder suspension and sedimentation. Results show that the higher quality of the PBG films was fabricated in higher relative humidity (RH) controlled conditions and low alcohol-content solvents. In addition, the surface tension and particle concentration were also influential factors to affect the PBG crystal growth. From the result of design of experimental (DOE), the final period of the sedimentation process was verified as the most influential stage of the formation of the PBG films. The optimal operating conditions of the PBG crystal fabrication were determined using the DOE data and the optimization approach. The minimum time of fabricating the high quality of PBG film was obtained under the optimum RH-Controlled conditions.