银铜双原子MACE法可控制备倒金字塔多晶黑硅的结构与性能

采用一步银铜双原子金属辅助化学腐蚀法,室温下在多晶硅表面制备纳米陷光结构,再利用纳米结构修正溶液在温度为50℃时对硅片进行各向异性重构,可控制备出不同尺寸的倒金字塔陷光结构.用分光光度计测量了多晶硅表面的反射率,用扫描电镜观察了多晶硅表面形貌,用少子寿命测试仪测量了多晶硅钝化后的少子寿命.结果表明:影响倒金字塔结构尺寸的主要影响因素是制备态黑硅纳米结构的深度,当深度越深,最终形成的结构尺寸也越大;纳米结构修正溶液重构时间越长,所形成的倒金字塔结构尺寸越大,反射率也变大;经原子层沉积钝化后的倒金字塔结构中少子寿命随其尺寸的增大而增加;当倒金字塔边长为600nm时综合效果最佳,反射率为9.87%,少子寿命为37.82μs.

Structures and Properties of Black Multicrystalline Silicon with a Structure of Invert Pyramid Prepared Controllably by Ag and Cu Dually Assisted Chemical Etching Method

Using by the method of one step Ag and Cu dual elements based Metal Assisted Chemical Etching(MACE), a nano-light trapping structure was prepared at a room temperature on the surface of the multicrystalline silicon.Then, the silicon wafers were made an anisotropic refactoring using by a Nano Structure Rebuilding (NSR) solution at a temperature of 50℃, so that the invert pyramid light trapping structures with different sizes were prepared.The reflectance and surface morphologies of multicrystalline silicon, and the minority carrier lifetime of the passivated multicrystalline silicon were measured by spectrophotometer, scanning electron microscopy and Sinton WCT-120 tool respectively.The results show that, the main factor to affect the final size of invert pyramid structure is the depth of the as-etched nanostructure.The deeper the depth is, the larger the final size of invert pyramid structure becomes.With the increase of NSR refactoring time, the size of the invert pyramid structure goes larger and the reflectance becomes higher too.While the minority carrier lifetime increases with the increasing of the size of invert pyramids after atomic layer deposition passivating, one should make a balance between anti-reflection result and passivation effect.An invert pyramid with an edge length of 600 nm is found to be an optimal size, corresponding a reflectance of 9.87% and a minority carrier lifetime of 37.82 μs.