不同維度氧化鋅材料之製備與特性分析
No Thumbnail Available
Date
2005
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
氧化鋅為一寬能帶間隙Ⅱ-Ⅵ族半導體材料，並且在不同維度具備非常吸引人的特性。例如在室溫時，光波長範圍0.4~2 um有很高的光穿透性、高壓電性、擁有較大的電光係數、高發光效率及高激發(態)束縛能。
本研究中透過汽-液-固相(VLS)生長機制，並使用金與氧化鋅在基板上當作催化劑在900oC條件下成長氧化鋅奈米線；另外使用溶膠凝膠法中的旋轉塗佈法製備氧化鋅薄膜與氧化鋅粉末，其中氧化鋅薄膜主要係沉積於矽晶圓(100)及康寧玻璃7059基板上。結構分析以X-ray、SEM、AFM為主，光學特性分析則使用UV-VIS分光光譜儀及光激發螢光光譜儀。
研究結果顯示，溫度、時間、觸媒等條件會對利用VLS機制成長之氧化鋅奈米線有很大的影響。氧化鋅奈米線直徑和觸媒層的晶粒尺寸有關，且隨著沉積時間的長短而變化。使用溶膠凝膠法製備之氧化鋅薄膜具有顯著的c軸優先成長取向及高透明性，晶粒尺寸亦隨著熱處理溫度增加而增加，在750oC時，晶粒尺寸約為50 nm；光激發光譜中，可以觀察到薄膜發光波長約為380 nm和520 nm，其特性亦與摻雜物有關，薄膜摻雜1.6 at%的鋁含量並在750oC作熱處理有最小電阻值，約為3 ohm-cm，薄膜穿透率在可見光範圍約有85~90 %的透光率。以溶膠凝膠法合成之氧化鋅粉末其結構呈現多方向性生長特性。由實驗結果得知，熱處理溫度是影響氧化鋅的結構與光電特性最主要的因素。
Zinc oxide (ZnO) is a wide band gap II-VI semiconductor material having very attractive properties at room temperature, such as high transparency in the 0.4~2 m optical wavelength range, high piezoelectric constant, large electro-optic coefficient, high luminescence efficiency and large exciting bind energy. In this study, ZnO nanowires were grown at about 900oC by using gold and ZnO as catalyst via Vapor-Liquid-Solid (VLS) mechanism. Furthermore, the thin film and powder of ZnO were prepared by sol-gel spin coating method. The ZnO thin films were coated on Si (100) and corning 7059 glass substrate. Structural investigation including surface morphology and microstructure was carried out by XRD, SEM and AFM measurements. Also, optical properties were determined by photoluminescence (PL) and UV-VIS spectrum analyses. The growth of ZnO nanowires has been achieved by vapor-liquid-solid method. According to the experimental results, deposition temperature, deposition time and catalysts are the main factors on the growth properties of ZnO nanowires. The diameter of ZnO nanowires depended on the grain size of catalyst layer and the deposition time. Highly preferential c-axis orientation ZnO thin films with transparent and conductive properties have been prepared by the sol-gel method. The SEM images show that the grains sizes increased with increasing annealing temperature up to 750oC, where the particle size was about 50 nm. Furthermore, PL spectra showed two main peaks centered at about 380 nm (UV) and 520 nm (green). The minimum sheet resistance, around 3 ohm-cm, was obtained for the thin film doped with 1.6 at. % Al (AZO) and then annealed at 750 oC. Meanwhile, all AZO films deposited on glass are very transparent, around 85 ~ 95 % transmittance, within the visible wavelength region. The powders of ZnO were achieved by the sol-gel route. Their structure showed a multi-direction growth property. It was proposed that thermal treatment temperature plays an important role on the structural and optical properties of ZnO.
Zinc oxide (ZnO) is a wide band gap II-VI semiconductor material having very attractive properties at room temperature, such as high transparency in the 0.4~2 m optical wavelength range, high piezoelectric constant, large electro-optic coefficient, high luminescence efficiency and large exciting bind energy. In this study, ZnO nanowires were grown at about 900oC by using gold and ZnO as catalyst via Vapor-Liquid-Solid (VLS) mechanism. Furthermore, the thin film and powder of ZnO were prepared by sol-gel spin coating method. The ZnO thin films were coated on Si (100) and corning 7059 glass substrate. Structural investigation including surface morphology and microstructure was carried out by XRD, SEM and AFM measurements. Also, optical properties were determined by photoluminescence (PL) and UV-VIS spectrum analyses. The growth of ZnO nanowires has been achieved by vapor-liquid-solid method. According to the experimental results, deposition temperature, deposition time and catalysts are the main factors on the growth properties of ZnO nanowires. The diameter of ZnO nanowires depended on the grain size of catalyst layer and the deposition time. Highly preferential c-axis orientation ZnO thin films with transparent and conductive properties have been prepared by the sol-gel method. The SEM images show that the grains sizes increased with increasing annealing temperature up to 750oC, where the particle size was about 50 nm. Furthermore, PL spectra showed two main peaks centered at about 380 nm (UV) and 520 nm (green). The minimum sheet resistance, around 3 ohm-cm, was obtained for the thin film doped with 1.6 at. % Al (AZO) and then annealed at 750 oC. Meanwhile, all AZO films deposited on glass are very transparent, around 85 ~ 95 % transmittance, within the visible wavelength region. The powders of ZnO were achieved by the sol-gel route. Their structure showed a multi-direction growth property. It was proposed that thermal treatment temperature plays an important role on the structural and optical properties of ZnO.
Description
Keywords
溶膠凝膠法, 氧化鋅奈米線, 氧化鋅薄膜, 氧化鋅粉末, 汽-液-固相生長機制, sol-gel method, ZnO nanowires, ZnO thin films, ZnO powder, vapor-liquid-solid mechanism