Table 1.
Field emission properties of the various CNT emitters on sharp substrates
| Substrate | Production method | Emission area (cm2) | Best emission | Vacuum ambient (Pa) | Stability | Refs. |
|---|---|---|---|---|---|---|
| Conical tip | Plasma-enhanced CVD | 1.6 × 10−6 | 26 μA, 1.2 kV/250 μm | 4 × 10−7 | 10 μA, >20 h | [6] |
| Inductively coupled plasma CVD | ~3 × 10−8(1 μm end diameter) | 51 μA, 1 kV/250 μm | 1.06 × 10−5 | 10 μA, >40 h | [16] | |
| Pyrolysis of ferrocene | 6.7 × 10−7 | 1 mA, 16.5 kV/5 cm | 1 × 10−8 | 100 μA, >180 min | [17] | |
| Plasma-enhanced CVD | 1.2 × 10−9 | ~100 μA, 2.7 kV/1 mm | 1 × 10−8 | 80 μA, >100 h | [18] | |
| Wire | Arc | ~5.9 × 10−4(125 μm ϕ, 0.3 mm length) | 7 mA/cm2, 6 kV/1 mm | 2.6 × 10−4 | 2 mA/cm2, >15 h | [34] |
| Plasma-enhanced CVD | ~7.9 × 10−4(50 μm ϕ, 1 mm length) | 1 mA, 4.3 V/1 mm | 1 × 10−9 | 1 mA, >5,000 h | [35] | |
| Flat plate | Arc/Ag paste | 2 × 10−2 | 10 mA/cm2, 2.2 V/μm | ~1 × 10−6 | ~210 μA, >8,000 h | [36] |
| Printed CNT | 2.83 | 8 mA, 1.55 kV/0.5 mm | ~1.3 × 10−5 | ~0.6 mA, >100 h | [4] | |
| CVD | 5.6 × 10−3 | 100 mA/cm2, 12 kV/1 mm | ~1.3 × 10−5 | ~300 μA, >15 h | [8] | |
| Flat tip | CVD/Ag NP paste | 4.9 × 10−4 | 465 μA, 6.6 kV/2 mm | ~1 × 10−3 | ~100 μA, >40 h |