Lower reflectivity and higher minority carrier lifetime of hand-tailored porous silicon

• Published in: Journal of semiconductors Vol. 30; no. 7; pp. 15 - 18
• Main Author: 张楠生 马忠权 周呈悦 何波
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.07.2009
• Subjects: 低反射率; 光电调制器; 化学选择性; 多孔硅; 太阳能电池; 少数载流子寿命; 晶体表面; 氧化时间
• ISSN: 1674-4926
• DOI: 10.1088/1674-4926/30/7/072004

Solar cell grade crystalline silicon with very low reflectivity has been obtained by electrochemically selective erosion.The porous silicon（PS） structure with a mixture of nano-and micro-crystals shows good antireflection properties on the surface layer, which has potential for application in commercial silicon photovoltaic devices after optimization.The morphology and reflectivity of the PS layers are easily modulated by controlling the electrochemical formation conditions（i.e., the current density and the anodization time）.It has been shown that much a lower reflectivity of approximately 1.42% in the range 380-1100 nm is realized by using optimized conditions.In addition, the minority carrier lifetime of the PS after removing the phosphorus silicon layer is measured to be ～3.19 μs.These values are very close to the reflectivity and the minority carrier lifetime of Si3N4 as a passivation layer on a bulk silicon-based solar cell（0.33% and 3.03 μs, respectively）.