Effect of substrate temperature on microstructure and optical properties of single-phased Ag20 film deposited by using radio-frequency reactive magnetron sputtering method

Using a radio-frequency reactive magnetron sputtering technique, a series of the single-phased Ag20 films are deposited in a mixture of oxygen and argon gas with a flow ratio of 2：3 by changing substrate temperature （Ts）. Effects of the Ts on the microstructure and optical properties of the films are investigated by using X-ray diffractometry, scanning electron microscopy and spectrophotometry. The single-phased Ag20 films deposited at values of Ts below 200℃ are （111） preferentially oriented, which may be due to the smallest free energy of the （111） crystalline face. The film crystallization becomes poor as the value of Ts increases from 100℃ to 225℃. In particular, the Ag20 film deposited at Ts=225℃ loses the （111） preferential orientation. Correspondingly, the film surface morphology obviously evolves from a uniform and compact surface structure to a loose and gullied surface structure. With the increase of Ts value, the transmissivity and the reflectivity of the films in the transparent region are gradually reduced, while the absorptivity gradually increases, which may be attributed to an evolution of the crystalline structure and the surface morphology of the films.     

Effects of Rapid Thermal Processing on Microstructure and Optical Properties of As-Deposited Ag2O Films by Direct-Current Reactive Magnetron Sputtering

（111） preferentially oriented Ag2O film deposited by direct current reactive magnetron sputtering is annealed by rapid thermal processing at different annealing temperatures for 5 min. The film microstructure and optical properties are then characterized by x-ray diffractometry, scanning electron microscopy, and spectrophotometry, respectively. The results indicate that no clear Ag diffraction peak is discernable in the Ag2O film annealed below 200°C. In comparison, the Ag2O film annealed at 200°C begins to exhibit characteristic Ag diffraction peaks, and in particular the Ag2O film annealed at 250°C can demonstrate enhanced Ag diffraction peaks. This implies that the threshold of the thermal decomposition reaction to produce Ag particles is approximately 200°C for the Ag2O film. In addition, an evolution of the film surface morphology from compact and pyramid-like to a rough and porous structure clearly occurred with increasing annealing temperature. The porous structure might be attributable to the escape of the oxygen produced during annealing, while the rough surface might originate from the reconstruction of the surface. The dispersion of interference peak intensity in the reflectance and transmission spectra could be attributed to the Ag particles produced. The lowered crystallinity and Ag particles produced induce a lattice defect, which results in an enhanced transmissivity in the violet region and a weakened transmissivity in the infrared region.     

p型微晶硅薄膜的沉积及其在微晶硅薄膜太阳电池中的应用

采用等离子体化学气相沉积（PECVD）方法制备了硼掺杂微晶硅薄膜和微晶硅薄膜太阳电池.研究了乙硼烷含量、p型膜厚度及沉积温度对硼掺杂薄膜生长特性和高沉积速率的电池性能的影响.通过对p型微晶硅薄膜沉积参数的优化,在本征层沉积速率为0.78nm/s的高沉积速率下,制备了效率为5.5%的单结微晶硅薄膜太阳电池.另外,对p型微晶硅薄膜的载流子疏输运机理进行了讨论.     

功率密度对VHF-PECVD制备μc-Si:H的影响

在不同功率密度下用甚高频化学气相沉积(VHF-PECVD)法制备了一系列微晶硅(μc-Si:H)薄膜,并对薄膜的微观结构进行了研究.重点研究了在较低的功率密度下,功率密度的改变对薄膜沉积速率和结晶状况的影响.结果表明,随着功率密度的提高,沉积速率逐渐加大,进一步提高功率密度时,沉积速率趋于饱和;与此同时,薄膜的孵化层厚度和形核密度随功率密度而变化.     

Microstructure and Optical Properties of AgxO Prepared by Direct-Current Magnetron-Sputtering Method

Two series of AgxO films are prepared on glass substrates by dc magnetron-sputtering method at room temperature and 90℃ under different oxygen to argon gas ratio （OAR） conditions. The mierostrueture is investigated by XRD and SEM in order to obtain the information on the component evolution of AgO＋Ag2O to Ag2O. Its optical properties are investigated by reflectance and absorption spectroscopy to extract the information on metallic and dielectric behaviour evolution of Ag2O, AgO and silver particles and the interband transition. The results indicate that the AgxO film prepared at room temperature is mainly made up of AgO and Ag2 O clusters while Ag2O is the primary component of AgxO prepared at 90℃. The AgxO film mainly consisting of the primary component shows indirect interband transition structure occurring at 2.89eV. Combination of increasing OAR and substrate temperature is an effective method to lower the threshold of thermal decomposition temperature of AgxO and to deal with the bottleneck of short-wavelength optical and magneto-optieM storage.     

非晶硅薄膜的快速热退火机理研究

采用RTA方法对PECVD沉积的a-S i:H薄膜进行固相晶化是近年来发展起来的一种制备多晶硅薄膜的新方法。通过研究不同退火工艺条件对薄膜结构的影响,来揭示快速热退火机理。研究表明短波长光(≤730nm)的量子效应在晶化过程中可能起着至关重要的作用。     

电子束蒸发制备ZnO:Al透明导电膜及其性能研究

在本实验中我们利用电子束蒸发方法在玻璃衬底上制备了ZnO:A l透明导电膜,并对所得样品在400℃下进行了退火处理。利用扫描电子显微镜观察了样品的表面形貌,利用分光光度计分析了样品的光学性质,结果表明所得样品在可见光范围具有较好的透光性。利用四探针对其进行了电学性质的测量,表明衬底温度为200℃时制备的样品电阻率可达6×10-3Ω.cm。     

低温沉积硅薄膜微结构的Raman分析

用Raman散射谱研究了以SiH4/H2为气源,用等离子体增强化学气相沉积技术,低温制备的一系列硅薄膜的微结构特征.结果表明:在常规气压和常规功率下,衬底温度在200～500 ℃之间,存在结晶最佳点,400 ℃结晶效果相对最好;在高压高功率下沉积和常压常功率下沉积相比,高压高功率更有利于薄膜晶化;低温短时的高气压高功率沉积,玻璃衬底与铝覆盖的玻璃衬底相比,玻璃上的硅薄膜晶粒尺寸更大,而铝覆盖的玻璃衬底上的硅薄膜的晶化率更高.     

多孔硅形成机理的逆结晶学模型

本文概述了多孔硅形成机理和现有模型.通过观察和分析多晶多孔硅化学腐蚀机理提出了一个新模型:多孔硅形成机理的逆结晶学模型.这个模型指出多晶多孔硅均匀形貌具有自选择性,而此自选择性受结晶学原理控制.此模型的提出对研究晶体生长有用.     

利用快速热退火法制备多晶硅薄膜

为了制备优质的多晶硅薄膜,该论文研究了非晶硅薄膜的快速热退火(RTA)技术.先利用PECVD设备沉积非晶硅薄膜,然后把其放入快速热退火炉中进行退火.退火前后的薄膜利用X射线衍射(XRD)仪、Raman光谱仪及扫描电子显微镜(SEM)测试其晶体结构及表面形貌,利用电导率测试设备测试其暗电导率.研究表明退火温度、退火时间以及沉积时的衬底温度对非晶硅薄膜的晶化都有很大的影响.