The Electronic Properties of Silicon Nanowires during Their Dissolution under Simulated Physiological Conditions
The Electronic Properties of Silicon Nanowires during Their Dissolution under Simulated Physiological Conditions
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DOI：
10.3390/app9040804
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
A. Steinbach;T. Sandner;Madeleine Nilsen;Ximeng Hua;R. Sivakumar;D. Geiger;A. Moeinian;S. Strehle
中科院分区：
文献类型：
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作者：
A. Steinbach;T. Sandner;Madeleine Nilsen;Ximeng Hua;R. Sivakumar;D. Geiger;A. Moeinian;S. Strehle
硅纳米线被认为是有前途的未来生物医学传感器。然而，它们在生理条件下的有限稳定性对传感器开发提出了挑战，并且需要显着改进对潜在效应的了解以及新的解决方案来增强硅纳米线的耐久性。在本研究中，我们推导出的溶解速率的硅纳米线在模拟生理条件下，从原子力显微镜测量。我们通过研究扭结硅纳米线p-n结的I-V特性，将纳米线直径的相关变化与电子性质的变化相关联。接触电位差测量和环境压力光电子能谱另外给洞察电子表面能带结构。在浸泡的第一周期间，n型硅纳米线的费米能级显著地向更高的能量移动，部分甚至高于导带边缘，这表现为电导率增加。大约一周后，费米能级稳定，电导率随着纳米线连续溶解引起的直径减小而一致地减小。我们的研究结果表明，生理环境可以大大影响硅纳米线器件的表面能带结构，并与它，它们的电子特性。因此，有必要研究这些影响，并找到策略，以获得可靠的生物医学传感器。
Silicon nanowires are considered promising future biomedical sensors. However, their limited stability under physiological conditions poses a challenge in sensor development and necessitates a significantly improved knowledge of underlying effects as well as new solutions to enhance silicon nanowire durability. In the present study, we deduced the dissolution rates of silicon nanowires under simulated physiological conditions from atomic force microscopy measurements. We correlated the relevant change in nanowire diameter to changes in the electronic properties by examining the I-V characteristics of kinked silicon nanowire p–n junctions. Contact potential difference measurements and ambient pressure photoemission spectroscopy additionally gave insights into the electronic surface band structure. During the first week of immersion, the Fermi level of n-type silicon nanowires shifted considerably to higher energies, partly even above the conduction band edge, which manifested in an increased conductivity. After about a week, the Fermi level stabilized and the conductivity decreased consistently with the decreasing diameter caused by continuous nanowire dissolution. Our results show that a physiological environment can substantially affect the surface band structure of silicon nanowire devices, and with it, their electronic properties. Therefore, it is necessary to study these effects and find strategies to gain reliable biomedical sensors.