Geometrical and Chemical-Dependent Hydrolysis Mechanisms of Silicon Nanomembranes for Biodegradable Electronics

作者：Liu Wang, Yuan Gao, Fanqi Dai, Deying Kong, Huachun Wang, Pengcheng Sun, Zhao Shi, Xing Sheng, Baoxing Xu, Lan Yin · 发表于：ACS Applied Materials & Interfaces · 年份：2019 · DOI：10.1021/acsami.9b03546 · 被引用次数：27 · 研究领域：Advanced Sensor and Energy Harvesting Materials、Nanowire Synthesis and Applications、Neuroscience and Neural Engineering

Biodegradable electronic devices that physically disappear in physiological or environmental solutions are of critical importance for widespread applications in healthcare management and environmental sustainability. The precise modulation of materials and devices dissolution with on-demand operational lifetime, however, remain a key challenge. Silicon nanomembranes (Si NMs) are one of the essential semiconductor components for high-performance biodegradable electronics at the system level. In this work, we discover unusual hydrolysis behaviors of Si NMs that are significantly dependent on the dimensions of devices as well as their surface chemistry statuses. The experiments show a pronounced increase in hydrolysis rates of p-type Si NMs with larger sizes, and mechanical stirring introduces a significant decrease in dissolution rates. The presence of phosphates and potassium ions in solutions, or lower dopant levels of Si NMs will facilitate the degradation of Si NMs and will also lead to a stronger size-dependent effect. Molecular dynamics simulations are performed to reveal ion adsorption mechanisms of Si NMs under different surface charge statuses and confirm our experimental observations. Through geometrical designs, Si NM-based electrode arrays with tunable dissolution lifetime are formed, and their electrochemical properties are analyzed in vitro. These results offer new controlling strategies to modulate the operational time frames of Si NMs through geometrical design ...