Zheng Mingli, Lin Shiquan, Xu Liang, Zhu Laipan, Wang Zhong Lin
Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Adv Mater. 2020 May;32(21):e2000928. doi: 10.1002/adma.202000928. Epub 2020 Apr 9.
Contact electrification (CE or triboelectrification) is a common phenomenon, which can occur for almost all types of materials. In previous studies, the CE between insulators and metals has been widely discussed, while CE involving semiconductors is only recently. Here, a tribo-current is generated by sliding an N-type diamond coated tip on a P-type or N-type Si wafers. The density of surface states of the Si wafer is changed by introducing different densities of doping. It is found that the tribo-current between two sliding semiconductors increases with increasing density of surface states of the semiconductor and the sliding load. The results suggest that the tribo-current is induced by the tribovoltaic effect, in which the electron-hole pairs at the sliding interface are excited by the energy release during friction, which may be due to the transition of electrons between the surface states during contact, or bond formation across the sliding interface. The electron-hole pairs at the sliding interface are subsequently separated by the built-in electric field at the PN or NN heterojunctions, which results in a tribo-current, in analogy to that which occurs in the photovoltaic effect.
接触起电（CE或摩擦起电）是一种常见现象，几乎所有类型的材料都可能发生。在以往的研究中，绝缘体与金属之间的接触起电已得到广泛讨论，而涉及半导体的接触起电则是最近才出现的。在此，通过在P型或N型硅片上滑动涂覆有N型金刚石的尖端来产生摩擦电流。通过引入不同的掺杂密度来改变硅片的表面态密度。研究发现，两个滑动半导体之间的摩擦电流随着半导体表面态密度和滑动负载的增加而增大。结果表明，摩擦电流是由摩擦光伏效应引起的，在该效应中，滑动界面处的电子 - 空穴对被摩擦过程中释放的能量激发，这可能是由于接触过程中表面态之间电子的跃迁，或者是跨越滑动界面形成键所致。滑动界面处的电子 - 空穴对随后被PN或NN异质结处的内建电场分离，从而产生摩擦电流，这类似于光伏效应中发生的情况。
