Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, USA.
Phys Chem Chem Phys. 2013 Jun 28;15(24):9862-70. doi: 10.1039/c3cp51835c. Epub 2013 May 16.
An effective and economical fabrication process for the synthesis of nanopore-type "black silicon", that significantly decreases reflectivity of silicon wafer surfaces, is reported using a room temperature one-step Ag-assisted chemical etching method. The effects on the surface morphology and the corresponding surface reflectivity of the concentration of the silver catalyst (500, 50, and 5 μM), the HF and H2O2 concentration in the silicon etchant, the HF : H2O2 ratio, and etching time have been investigated. Lower reflectivity is a balance between sufficient silver catalyst to create large numbers of nanopores on a silicon surface and excessive silver that brings deeply etched channels that would potentially short-circuit a solar cell junction. The lowest relative effective reflectivity (0.17% over a range of 300-1000 nm) occurs with a silver ion concentration of 50 μM, however, with the silver ion concentration decreases to 5 μM surfaces with a low relative effective reflectivity (2.60%) and a short nanopore length (<250 nm) can be obtained with 10 minute etching time, indicating that this method can be used as a simple (one-pot), low cost (low silver concentration), energy efficient (room temperature), method for the synthesis of anti-reflection layers for silicon-based solar cell applications.
一种有效的、经济的纳米孔型“黑硅”合成制造工艺，通过室温一步 Ag 辅助化学刻蚀方法显著降低了硅片表面的反射率。研究了银催化剂浓度（500、50 和 5 μM）、硅蚀刻剂中 HF 和 H2O2 浓度、HF:H2O2 比和蚀刻时间对表面形貌和相应表面反射率的影响。较低的反射率是在硅表面上形成大量纳米孔的足够银催化剂与过多的银之间的平衡，过多的银会带来深度蚀刻的通道，这可能会使太阳能电池结短路。在银离子浓度为 50 μM 时，相对有效反射率最低（300-1000nm 范围内为 0.17%），然而，当银离子浓度降低至 5 μM 时，通过 10 分钟的蚀刻时间可以获得具有低相对有效反射率（2.60%）和短纳米孔长度（<250nm）的表面，表明该方法可用作一种简单（一锅法）、低成本（低银浓度）、节能（室温）的方法，用于硅基太阳能电池应用的抗反射层的合成。
