Growth And Field Emission Properties Of B Doped SiC One-dimensional Nanostrudtures

SiC one-dimensional nanomaterials have been considered as an excellent candidate for field emitters.One of the important points to push forward their practical application is how to make the SiC nanostrcuters with enhanced field emission properties,namely,with a low turn-on field and excellent field emission stability.In present work,aimed to the exploration of the SiC field emitters with excellent FE performance,B-doped SiC nanowires have been fabricated via catalyst-assisted pyrolysis of polymeric precursors.The FE properties of the as-synthesized SiC nanostructurs have been investigated.The main research works are shown as bellow:Firstly,B-doped 3C-SiC nanowires with high quality have been synthesized with tailored doping levels via pyrolysis of polymeric precursors.The doping levels have been tailored by the used different pyrolysis temperatures and cooling rates.The experimental results suggest that the B doping levels could be increased with the raise of pyrolysis temperatures,and reduced with the increase of cooling rates.Secondly,the FE properties of the resultant B-doped SiC nanowires areinvestigated.The as-synthesized B-doped 3C-SiC nano wires exhibit excellent FE performances with a low turn-on field of 1.35 V/p.m under room temperature(?27?).The field emission stablities of B-doped 3C-SiC nanowires under room temperature(?27?)and 200 ? are measured to be of 14%and 11%,respectively.As compared to that of 22%of undoped 3C-SiC nanowires under 200 ?,the field emission stability of the 3C-SiC nanowires have been improved for 1 time,suggesting that the high-temperature FE stability of SiC nanowires could be significantly enhanced by the B dopants.Thirdly,the highly oriented B-doped SiC nanoarrays have been grown,and their temperature-dependent FE properties have studied Based on the experimental results,it could be concluded that the SiC nanoarrays are preferred to grow on the substrates of 6H-SiC and 4H-SiC with Au catalysts.It is found that the turn-on fields would be reduced from 3.09 V/?m to 0.85 V/?m for B-doped SiC nanoarrays grown on the 6H-SiC substrate with the temperature increase room temperature(?27?)to 400 ?.Their field emission stability is of 9%under room temperature.For the SiC nanoarrays grown on the 4H-SiC substrate,the turn-on fields would be reduced from 1.49 V/?m to 0.80 V/?m with the temperature increase in the range of room temperature(?27?)to 400?.Ther field emission stability worked under room temperature(?27 ?)is of 10%.