多层减反射膜对PERC太阳电池性能的影响

Influence of Multilayer Anti-reflection Coatings on Photoelectric Performances of PERC Solar Cells

优化晶体硅材料的光学特性,可有效提高晶体硅太阳能电池的光电转换效率。采用等离子体增强化学气相沉积(PECVD)法,在钝化发射极和背表面太阳电池(PERC)上成功制备出叠层结构的多层减反射薄膜提升硅材料的光学特性。研究结果表明,正面使用二氧化硅(SiO_(2))、氮化硅(SiNx)、氮氧化硅作为器件的叠层介质膜,将SiO_(2)/Si优良的界面性质和SiNx、氮氧化硅稳定的化学性质结合起来,使器件具有稳定的钝化特性。在叠层结构器件中,SiO_(2)作为缓冲层有利于减少光学损失和钝化表面缺陷态,薄的SiO_(2)几乎不会对多层减反结构产生干扰。SiNx可以有效降低光在器件表面的光学反射率,增加光的透射从而减少器件本身的光学损失。氨气有助于强化氢气在硅片表面的扩散,降低长波的光学损失和降低表面复合速率。PECVD制备的氮氧化硅在短波区域具有很好的吸收效果,表面复合速率明显下降,有效提高器件的短波响应。与此同时,经过热处理的减反射薄膜还可以钝化器件的缺陷,最终提升太阳能电池的减反射性能和钝化性能。

Optical property optimization of crystalline silicon materials can effectively improve the photoelectric conversion efficiency of crystalline silicon solar cells.Plasma Enhanced Chemical Vapor Deposition-method(PECVD)was used to successfully prepare multilayer anti-reflective coating on passivated emitted and rear cell(PERC)to enhance the optical properties of silicon materials.The results show that silicon dioxide,silicon nitride and silicon oxynitride are used as the dielectric film of the device,and the excellent interfacial properties of SiO_(2)/Si and the chemical properties of silicon nitride and silicon oxynitride are stabilized.Together,the device has stable passivation characteristics.In a stacked structure device,a thin layer of silicon dioxide acts as a buffer layer to facilitate quantum tunneling of electrons,and the thin silicon dioxide hardly interferes with the multilayer anti-reflection structure.Silicon nitride can effectively reduce the optical reflectivity of light on the surface of the device,increase the transmission of light and reduce the optical loss of the device itself.Ammonia helps to enhance the diffusion of hydrogen on the surface of the wafer,reducing the optical loss of long waves and the rate of surface recombination.The thin layer of silicon oxynitride prepared by PECVD has a good absorption effect in the short-wave region,and the surface recombination rate is significantly reduced,which effectively improves the short-wave response of the device.At the same time,the heat-treated anti-reflective film can also passivate the defects of the device,ultimately improving the antireflection performance and passivation performance of the solar cell.