纳米压印法制作亚波长结构PI减反射膜

Sub-wavelength structure Polyimide anti-reflection film with the technique of nano-imprint lithography( NIL)

为提高柔性基底太阳能电池光电转化效率,减少表面反射损失,用Tracepro光学仿真软件模拟设计亚波长结构减反射膜尺寸参数,仿真结果表明亚波长结构薄膜在纳米柱高度72 nm,占空比为0.5,光栅周期在300~440 nm处,光通量增强效果最佳.采用纳米压印技术,以多孔结构阳极氧化铝为模板,制作聚酰亚胺基底减反射膜.采用扫描电子显微镜和紫外-可见分光光度计研究了阳极氧化技术所制作的Al2O3模板及其纳米压印技术等工艺参数对PI薄膜透过率的影响.测试结果表明,在0.3 mol/L草酸溶液中,70 V恒压模式连续反应1 h条件下制备AAO模板,在280℃,800 kg压力条件下,热压印时间为10 min所得PI膜.在AM1.5大气质量条件下,UV-VIS透射光谱从440~1 000 nm区域,所制作的薄膜较原始PI膜的透过率提高2%~5%.

In this paper,a set of dimension parameters of the sub-wavelength structural anti-reflection film are designed to improve the photoelectric conversion efficiency of flexible substrate solar cell and reduce the surface reflection losses. The designed parameters are simulated in Trace Pro optical simulation software. The simulation results show that the flux enhancement effect is optimum when the Nano-column height is 72 nm,the duty ratio is0.5 and the grating period at 300-440 nm for the sub-wavelength structural film. Using Nano-imprinting technology,a polyimide membrane anti-reflection is fabricated based on the template of a vesicular structural anodic aluminum oxide（ AAO）. The influence of the technological parameters,which is of the fabricated AAO template and its Nano-imprinting technology,on the polyimide（ PI） transmittance of the films is tested by scanning electron microscope and ultraviolet-visible light detector. In experiments,we fabricate the AAO template in 0.3 mol / L oxalic acid solution consecutively reacting for 1 h in 70 V constant voltage mode. The PI film is obtained with the insulation being 10 min at 280 ℃ and 800 kg pressure. The test results show that when the transmission spectrum is from 440 nm to 1 000 nm in air mass 1.5（ AM1.5） atmosphere,the transmittance of the film is increased by 2% ~5% than the primitive PI film.