Slepchenkov Michael M, Nefedov Igor S, Glukhova Olga E
Department of Physics, Saratov State University, Astrakhanskaya street 83, 410012 Saratov, Russia.
School of Electrical Engineering, Aalto University, P.O. Box 13000, 00076 Aalto, Finland.
Materials (Basel). 2020 Jan 30;13(3):610. doi: 10.3390/ma13030610.
We investigate a process of controlling the electronic properties of a surface of nanoporous carbon glass-like thin films when the surface pores are filled with potassium atoms. The presence of impurities on the surface in the form of chemically adsorbed hydrogen and oxygen atoms, and also in the form of hydroxyl (OH) groups, is taken into account. It is found that even in the presence of impurities, the work function of a carbon nanoporous glass-like film can be reduced by several tenths of an electron volt when the nanopores are filled with potassium atoms. At the same time, almost all potassium atoms are ionized, losing one electron, which passes to the carbon framework of the film. This is due to the nanosizes of the pores in which the electron clouds of the potassium atom interact maximally with the electrons of the carbon framework. As a result, this leads to an improvement in the electrical conductivity and an increase in the electron density at the Fermi level. Thus, we conclude that an increase in the number of nanosized pores on the film surface makes it possible to effectively modify it, providing an effective control of the electronic structure and emission properties.
我们研究了一种在纳米多孔类玻璃碳薄膜表面孔隙填充钾原子时控制其表面电子性质的过程。考虑到表面存在化学吸附的氢原子、氧原子形式的杂质，以及羟基（OH）基团形式的杂质。研究发现，即使存在杂质，当纳米孔填充钾原子时，纳米多孔类玻璃碳薄膜的功函数也能降低十分之几电子伏特。与此同时，几乎所有钾原子都会电离，失去一个电子，该电子转移到薄膜的碳骨架上。这是由于孔隙的纳米尺寸使得钾原子的电子云与碳骨架的电子发生最大程度的相互作用。结果，这导致电导率提高以及费米能级处电子密度增加。因此，我们得出结论，薄膜表面纳米尺寸孔隙数量的增加使其能够得到有效改性，从而实现对电子结构和发射特性的有效控制。
