TY - JOUR

T1 - Field emission stability of anodic aluminum oxide carbon nanotube field emitter in the triode structure

AU - Li, Yi-Ming

AU - Cheng, Hui Wen

PY - 2009/5

Y1 - 2009/5

N2 - In this work, fabricated field emission (FE) triode arrays with the anodic aluminum oxide (AAO) template carbon nanotube (CNTs) as the field emitters are numerically analyzed. To obtain physically sound self-consistent solution, a set of Maxwell's equations coupling with Lorentz equation are solved simultaneously using a finite difference time domain particle-in-cell method. The FE current is then computed with the Fowler-Nordheim equation. To validate the simulation model, we firstly calibrate the collected electron current density between the measured AAO-CNT5 and calculated result. The FE current is dominated by, such as density, height, diameter, and tilt angle of CNT5, and applied bias, respectively. A high density of CNTs will result in strong screening effect among adjacent CNT5 and reduce the magnitude of electric field. Consequently, it significantly affects the emitted and collected electron current densities. However, the structure with much higher density of CNTs obviously emits more stable current than that of a low density of CNT5. There is an optimal setting on the height and diameter of the CNTs within the explored structure which exhibits the highest current density. When we vary the density of CNTs, the structure with high density (say the number of CNT5 is greater than 30) shows the most stable and smallest fluctuation on the current density against the randomly generated samples of the height and tilt angle of CNTs.

AB - In this work, fabricated field emission (FE) triode arrays with the anodic aluminum oxide (AAO) template carbon nanotube (CNTs) as the field emitters are numerically analyzed. To obtain physically sound self-consistent solution, a set of Maxwell's equations coupling with Lorentz equation are solved simultaneously using a finite difference time domain particle-in-cell method. The FE current is then computed with the Fowler-Nordheim equation. To validate the simulation model, we firstly calibrate the collected electron current density between the measured AAO-CNT5 and calculated result. The FE current is dominated by, such as density, height, diameter, and tilt angle of CNT5, and applied bias, respectively. A high density of CNTs will result in strong screening effect among adjacent CNT5 and reduce the magnitude of electric field. Consequently, it significantly affects the emitted and collected electron current densities. However, the structure with much higher density of CNTs obviously emits more stable current than that of a low density of CNT5. There is an optimal setting on the height and diameter of the CNTs within the explored structure which exhibits the highest current density. When we vary the density of CNTs, the structure with high density (say the number of CNT5 is greater than 30) shows the most stable and smallest fluctuation on the current density against the randomly generated samples of the height and tilt angle of CNTs.

KW - AAO-CNT5

KW - Emitted and collected electron current density

KW - Field emission

KW - Fluctuation

KW - Fowler-nordheim equation

KW - Lorentz equation

KW - Maxwell equation

KW - Numerical simulation

KW - Optimal structure parameters.

KW - Triode structure

UR - http://www.scopus.com/inward/record.url?scp=67649200083&partnerID=8YFLogxK

U2 - 10.1166/jnn.2009.VC05

DO - 10.1166/jnn.2009.VC05

M3 - Article

C2 - 19453007

AN - SCOPUS:67649200083

SN - 1533-4880

VL - 9

SP - 3301

EP - 3307

JO - Journal of Nanoscience and Nanotechnology

JF - Journal of Nanoscience and Nanotechnology

IS - 5

ER -