金屬氧化物半導體特性及其阻值調整應用於氣體感測器與液晶透鏡

Abstract

本論文之主軸為將金屬氧化物應用於氣體感測元件與液晶透鏡上，分別使用氧化鋅(ZnO)以及氧化銦鋅(IZO)此兩種材料。氣體感測部分為利用水熱法(hydrothermal process)方式成長氧化鋅奈米柱製成一氧化氮氣體感測元件。本論文使用銀奈米線製成垂直式電極結構取代一般常見之水平電極結構，並透過改善各種不同的製程條件，如晶種層厚度、奈米柱成長時間與晶種層退火等，大幅提升元件對一氧化氮的感測能力。在本論文中的氣體感測元件，在室溫及乾燥空氣環境下對於100ppb的一氧化氮氣體最高有29.9%的響應值，而此氣體感測元件所能感測一氧化氮的最低濃度為10ppb，最高有6.8%的響應值。 本論文亦透過改變氧化銦鋅之預處理方式，達到不同的阻值，並將此薄膜作為高阻抗層成功應用於大孔徑(直徑20mm)液晶透鏡。此高阻抗層還可利用改變薄膜之預處理的方式，達到一趨近線性變化的阻值，未來透過此方式在同一層薄膜上擁有不同的阻值分佈，預期能夠改善大孔徑液晶透鏡的成像效果。

The aim of this thesis is using metal oxide semiconductor for NO gas sensor and liquid crystal lens applications. For NO gas sensor, we use hydrothermal process to grow ZnO nanorods on ITO glass substrates. For electrical measurement, silver nanowires electrodes were dropped onto the ZnO nanorods, and Al were deposited as auxiliary electrodes. We changed different process conditions to improve the gas sensing performance of our devices. The maximum response for 100ppb NO gas is 29.9% at room temperature. The lowest concentration for detection is 10ppb NO gas, which has response of 6.8%. For liquid crystal lens, we successfully demonstrated that the IZO thin film can use as a high resistance layer in the large aperture (diameter: 20mm) liquid crystal lens. Moreover, the sheet resistance of the high resistance layer can be modified by changing the pretreatment of the thin film.