Abstract In this study, nanostructured pyramidal black silicon is prepared by metal assisted chemical etching method, in which the silver nitrate (AgNO3) is used as the metal catalyst. Effects of the concentration of AgNO3 on passivation and optical properties of the black silicon are investigated. The experimental results show that at the AgNO3 concentration of 0.03 M, the nanostructure length is about 300 nm, and the reflectance of the black silicon with a stack of silicon nitride (SiNx) and aluminum oxide (Al2O3) is 0.8%, which is comparable to that of the conventional black silicon with micrometer-long nanowires. In addition, an acceptably low surface recombination rate of 42 cm/s can be obtained. Plasma chemical vapor deposited SiNx is deposited well on the top of nanostructures of black silicon, but shows poor coverage at the bottom region. Spatial atomic layer deposited Al2O3 can conformally cover the nanostructures with high passivation quality. Simulation result indicates an improvement of 5.5% of conversion efficiency for the nanostructured pyramidal black silicon solar cell compared to industrial silicon solar cell. The short nanostructured pyramidal surface with low reflectance and high passivation is expected to be helpful for black silicon technology applied to photovoltaic applications.

中文翻译：

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具有超低反射率和高钝化的纳米结构锥形黑硅

摘要 本研究以硝酸银(AgNO3)为金属催化剂，采用金属辅助化学蚀刻法制备纳米结构的锥形黑硅。研究了 AgNO3 浓度对黑硅钝化和光学性能的影响。实验结果表明，在0.03 M的AgNO3浓度下，纳米结构长度约为300 nm，具有氮化硅（SiNx）和氧化铝（Al2O3）叠层的黑硅反射率为0.8%，具有可比性与具有微米长纳米线的传统黑硅相比。此外，可以获得 42 cm/s 的可接受的低表面复合率。等离子体化学气相沉积的 SiNx 在黑硅纳米结构的顶部沉积得很好，但在底部区域显示出较差的覆盖率。空间原子层沉积的 Al2O3 可以保形覆盖纳米结构，具有高钝化质量。仿真结果表明，与工业硅太阳能电池相比，纳米结构锥形黑硅太阳能电池的转换效率提高了 5.5%。具有低反射率和高钝化的短纳米结构金字塔表面有望有助于应用于光伏应用的黑硅技术。