End potential barriers of single-walled carbon nanotubes and their role in field

2019-12-05 20:13:37

single potential field density emission

责任者: Ji Luo;Peng, L.-M.;Xue, Z.Q.;Wu, J.L. 单位: Dept. of Electron., Peking Univ., Beijing, China 来源出处: Physical Review B (Condensed Matter and Materials Physics)(Phys. Rev, B, Condens, Matter Mater. Phys. (USA)),2002/10/15,66(15):155407-1 摘要: Very short single-walled carbon nanotube (SWNT) models carrying a net negative charge are employed to simulate tube tips in field emission situations and then, density-functional theory calculations are carried out on these models to obtain their potential barrier shapes and electric-field distributions. These results, incorporated with the SWNT band structures, are used to analyze field emission properties of SWNTs. It is shown that theoretically, low applied voltage (about ten and several volts) might generate emission current as large as 100 nanoamperes from a single SWNT, and closed end geometries lead to a better emission effect, due to their higher electron energy. In addition, limitations of the adopted theoretical approach are discussed, along with its possible improvement 关键词: band structure;carbon nanotubes;density functional theory;electron field emission;field emission;end potential barriers;very short single-walled C nanotube models;net negative charge;tube tip simulation;density functional theory calculations;potential barrier shapes;electric field distributions;band structures;low applied voltage;emission current;electron energy;100 nA;C