Metal-assisted chemical etching (MACE) is a widely applied process for fabricating Si nanostructures. As an electroless process, it does not require a counter electrode, and it is usually considered that only holes in the Si valence band contribute to the process. In this work, a charge carrier collecting p–n junction structure coated with silver nanoparticles is used to demonstrate that also electrons in the conduction band play a fundamental role in MACE, and enable an electroless chemical energy conversion process that was not previously reported. The studied structures generate electricity at a power density of 0.43 mW/cm² during MACE. This necessitates reformulating the microscopic electrochemical description of the Si-metal-oxidant nanosystems to separately account for electron and hole injections into the conduction and valence band of Si. Our work provides new insight into the fundamentals of MACE and demonstrates a radically new route to chemical energy conversion by solar cell-inspired devices.

中文翻译：

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金属辅助化学蚀刻中的电子注入作为化学发电的基本机制

金属辅助化学蚀刻 (MACE) 是一种广泛应用的制备 Si 纳米结构的工艺。作为无电镀工艺，它不需要对电极，通常认为只有Si价带中的空穴有助于该工艺。在这项工作中，使用涂有银纳米颗粒的电荷载流子收集 p-n 结结构来证明导带中的电子在 MACE 中也起着基本作用，并实现了以前未报道过的化学能量转换过程。^{所研究的结构以 0.43 mW/cm 2}的功率密度发电在 MACE 期间。这需要重新制定硅金属氧化剂纳米系统的微观电化学描述，以分别考虑电子和空穴注入到硅的导带和价带中。我们的工作为 MACE 的基本原理提供了新的见解，并展示了一种由太阳能电池启发的设备进行化学能转换的全新途径。