Effect of carbon atoms on the reliability of potassium-ion electrets used in vibration-powered generators
Effect of carbon atoms on the reliability of potassium-ion electrets used in vibration-powered generators
复制标题
碳原子对振动发电机用钾离子驻极体可靠性的影响
DOI：
10.35848/1347-4065/ac6a3f
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发表时间：
2022
影响因子：
1.5
通讯作者：
K. Shiraishi
中科院分区：
文献类型：
--
作者：
Yoshiki Ohata;M. Araidai;Y. Shibata;G. Hashiguchi;K. Shiraishi
钾离子驻极体是振动式微型机电发电机中的关键元件，它几乎可以永久储存负电荷。然而，我们的实验表明，当在制备过程中使用碳化硅平板而不是通常的二氧化硅平板时，钾离子驻极体的电荷储存能力严重下降，这表明碳掺杂的负面影响。利用第一性原理分子动力学计算方法，从理论上研究了非晶态SiO_2(a-SiO_2)在含和不含K、C原子时的原子和电子结构。我们的计算表明，在没有碳污染的情况下，负电荷在五配位的硅原子中积累。然而，钾离子驻极体的碳污染导致二氧化硅中的氧缺乏，阻碍了五配位硅原子的形成。因此，碳污染会导致钾离子驻极体的负电荷储存能力下降。
Potassium-ion electrets, which are key elements in vibration-powered microelectromechanical generators, can store negative charge almost permanently. However, our experiments show that the charge storing capability of potassium ion electrets is severely degraded when a SiC plate instead of the usual SiO2 plate is used in the fabrication process, indicating the negative influence of carbon incorporation. We theoretically studied the atomic and electronic structures of amorphous silica (a-SiO2) with and without potassium and carbon atoms using first-principles molecular-dynamics calculations. Our calculations show that negative charge accumulates in fivefold-coordinated Si atoms without carbon contamination. However, carbon contamination of the potassium-ion electret causes oxygen deficiencies in SiO2, hindering the formation of fivefold-coordinated Si atoms. As a result, carbon contamination causes degradation of the negative charge storing capability of potassium-ion electrets.