Effect of arrangement of pillar array of aligned carbon nanotube bundles on its field-emission characteristic

We investigated the properties of field emission from a pillar array of aligned carbon nanotube (CNT) bundles, which were fabricated on a Si substrate by thermal chemical vapor deposition. To explore the influence of the pillar arrangement on its field emission, the ratio of interpillar distance (R) to pillar height (H), R/H, was investigated as a function of H by changing H while maintaining R at 100 mu m. The most-enhanced field concentration was obtained at R/H similar to 6, although we previously reported that the optimal configuration of pillars for R = 250 mu m was a ratio of R/H = 2. These results show that the optimal R/H for greatest field emission from the CNT pillar array is dependent on R. (C) 2007 Elsevier B.V. All rights reserved.