纳秒脉冲激光器制备的Si表面宽带抗反射杂化结构

Hybrid microstructures on Si surface formed by nanosecond pulse laser for broadband antireflection

提出了一种通过纳秒脉冲激光器微加工制作的杂化准微金字塔型结构,与未经处理的均匀准微金字塔型结构相比,平均反射率下降了15%。通过实验,系统研究了激光能量密度、脉冲个数和图案间距对反射性能的影响。结果表明,反射率随图案间距的增加而增加,随着脉冲数增加而减少,当激光能量密度在4.83J/cm2时获得最小反射。这种技术用具有普通纵横比的微杂化结构替代高纵横比的非杂化结构,获得宽带抗反射性能,成本更低。通过优化激光加工参数能获得较高的抗反射性能。

In order to reduce the average reflectance of broadband antireflection surfaces,a hybrid quasi-micro-pyramid structure is fabricated via nanosecond pulse laser micro-processing,which demonstrates a 15% drop in average reflectance as compared with the uniform quasi-micro-pyramid structures.The effects of laser fluence,pulse nu mber and designed pitch are also studied experimentally and systematically.The results s how that the reflection increases with the pattern pitch,decreases with pulse number ,and a minimum in reflection is achieved at a laser fluence of 4.83J/cm2.A hybrid st ructure is fabricated by nanosecond pulse laser with multiple scanning,which demonstra tes a lower reflection with a decrease of 7% and 35% in average and peak reflectances compared with its corresponding uniform structures.The demonstrated method provides an alternative and low-cost solution for broadband anti-reflection by hybrid stru ctures with normal aspect ratio rather than uniform structures with high aspect ratio. Higher antireflection performance can be expected by optimizing the laser processing parameters.