华北电力大学 新能源电力系统国家重点实验室, 北京 102206
采用磁控溅射法在Si衬底上制备了SiO2介质膜, 系统地研究了SiO2膜引入对Ag纳米颗粒的表面覆盖率、形貌、形成机理和光学性质的影响.研究发现引入SiO2介质膜后, Ag纳米颗粒的表面覆盖率显著增加, 平均粒径明显降低.基于现有的Ag纳米颗粒形成机理, 提出了粗糙表面Ag膜断裂模型以解释其形貌发生变化的原因.紫外-可见光分光光度计测试表明, 引入SiO2膜并优化其厚度, 可使Ag纳米颗粒的偶极消光峰最大红移86nm, 但消光峰强度明显下降.数值模拟计算表明, 引入SiO2膜的Ag纳米颗粒所能散射的光子数量最小减少2×1018个.因此, 在Si衬底上沉积SiO2膜, 不利于Ag纳米颗粒陷光性能的提高.
二氧化硅膜 银纳米颗粒 形成机理 消光谱 陷光性能 Silica film Ag nanoparticles Formation mechanism Extinction spectra Light trapping performance
Author Affiliations
Abstract
1 Beijing Key Laboratory of New and Renewable Energy, North China Electric Power University, Beijing 102206, China
2 Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
3 National Engineering Research Center for Optoelectronic Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
Forward-scattering efficiency (FSE) is first proposed when an Ag nanoparticle serves as the light-trapping structure for thin-film (TF) solar cells because the Ag nanoparticle’s light-trapping efficiency lies on the light-scattering direction of metal nanoparticles. Based on FSE analysis of Ag nanoparticles with radii of 53 and 88 nm, the forward-scattering spectra and light-trapping efficiencies are calculated. The contributions of dipole and quadrupole modes to light-trapping effect are also analyzed quantitatively. When the surface coverage of Ag nanoparticles is 5%, light-trapping efficiencies are 15.5% and 32.3%, respectively, for 53- and 88-nm Ag nanoparticles. Results indicate that the plasmon quadrupole mode resonance of Ag nanoparticles could further enhance the light-trapping effect for TF solar cells.
薄膜太阳电池 金属纳米颗粒 陷光效率 前向散射 290.4020 Mie theory 240.6680 Surface plasmons 350.6050 Solar energy 290.2558 Forward scattering Chinese Optics Letters
2011, 9(3): 032901
