Synthesis and Enhanced Field-Emission of Thin-Walled, Open-Ended, and Well-Aligned N-Doped Carbon Nanotubes

Table 2 Field-emission data of different samples, here E_to (V/μm) and E_th (V/μm) are turn-on electric field and threshold electric field, respectively; β is the field-enhancement factor

Samples	E_to (V/μm)	E_th (V/μm)	β	Data source
ZnO nanoneedle arrays	5.7	–	793	[34]
ZnS heterostructures	2.66	4.01	>2,600	[35]
Aligned N-doped CNTs	2.30	–	–	[14]
MWCNT	1.88	2.40	1.86 × 10⁴	[37]
SWCNTs	–	2.40	3,392	[38]
Aligned CNTs	1.13	2.25	6,222	[18]
N-doped DWCNTs	~0.9	1.78	3,399	[39]
CuO nanoneedle arrays	0.85	–	–	[36]
FeNi-CNTs	0.30	0.65	2.48 × 10⁴	[5]
ANCNT(780)^a	0.45	0.60	6.41 × 10⁴	This study
ANCNT(820)^a	0.35	0.55	7.79 × 10⁴	This study
ANCNT(860)^a	0.27	0.49	1.09 × 10⁵	This study

^aANCNT (860), ANCNT (820), and ANCNT (780) denote the samples prepared by acetonitrile at a growth temperature of 860, 820, and 780°C, respectively