- 學位論文
紅外線熱發射器效率之增強與在微小化CO2氣體偵測系統之應用
Enhancing the Emission Efficiency of Infrared Thermal Emitter and Its Application on Miniature CO2 Gas Sensing System
摘要
本文主要探討紅外線熱輻射器效率增強之方法，並將影響發射效率之相關參數最佳化，而後將此高發射率之元件應用於微小化的二氧化碳偵測系統。首先將元件的基材薄化並設計電極圖形以聚集熱源，減少基材對熱的吸收，而後探討元件上層金屬的厚度以及孔洞面積之分佈對於發光效率的影響，並找出最佳之參數，最後結合金屬奈米粒子於週期性孔洞後更加提升了元件的發射效率。結合這些最佳值所做出來的紅外光熱輻射器其發光效率較原始熱輻射器之效率高出76 %。接著將此高發射效率之熱輻射器應用於自行設計之微小化二氧化碳偵測系統，結合放大電路加強訊號及反射鏡組延長吸收路徑，偵測的靈敏度大幅提升，得到相當線性的氣體濃度與測得訊號之趨勢，並建立一之可信賴資料庫。因此，本研究實現了一微小化且穩定的二氧化碳偵測系統，未來可應用於環境安全及健康照護，對於可攜式氣體偵測系統之發展也相當有幫助。
並列摘要
In this thesis, the emission intensity and conversion efficiency of WTE is optimized. Several techniques are studied. First, silicon substrate is thinned by wet etching and the relationship between substrate thickness and power consumption are measured. The minimum thickness for fabrication is determined for reducing heat dissipation. Then the input power is decreased and the conversion efficiency is increased by concentrating the heating area through appropriate design of the electrode. Furthermore, the optimized hole area distribution and thickness of top metal layer for reaching much higher emission intensity are also determined. It is also demonstrated that incorporating random metallic nanoparticles formed by rapid thermal annealing in periodic hole arrays could effectively enhance the emissivity of WTE. Different kinds of metallic film which result in different sizes and randomly distributed nanoparticles are investigated. And gold NPs is the best for enhancing emissivity. Finally, it is found that the emissivity increased 76% as compared to the traditional WTE by combining all the optimized factors. Moreover, the WTE device with high emissivity has also been used in the miniatured CO2 sensing system. In addition, with the interface circuits and mirror module, the sensitivity of detection is enhanced dramatically. The trend between delta voltage and CO2 concentration in system is very stable. So, the stable miniature CO2 detection system is realized and a reliable database for the environmental safety and healthcare is set up. This result will be beneficial for the portable biomedical device in the future.