Direct observation of electron emission from the grain boundaries of chemical vapour deposition diamond films by tunneling atomic force microscopy

2014 ◽  
Vol 104 (17) ◽  
pp. 171907 ◽  
Author(s):  
Vijay Chatterjee ◽  
Robert Harniman ◽  
Paul W. May ◽  
P. K. Barhai
2018 ◽  
Vol 42 (2) ◽  
pp. 73-76 ◽  
Author(s):  
Azadeh Jafari ◽  
Mohammad Mosavat ◽  
Alireza Meidanchi ◽  
H. Hossienkhani

Boron carbide nanostructures were grown on Si wafers through introduction of a mixture of B2O3 dissolved in methanol using hot filament chemical vapour deposition. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), Raman spectroscopy and the four-point probe technique were applied to characterise the properties of the boron carbide nanostructures. The XRD results showed that two kinds of boron carbide chemical compounds (B4C and B2C2) were deposited and the effect of boron concentration was significant. The FESEM images showed that the boron carbide nanostructures are made of crystal clusters with a cauliflower-like shape, in which the grain boundaries appear more clearly with increasing boron concentration. In addition, the AFM results showed that the surface roughness of the boron carbide films decreased with increasing boron concentration due to grain boundary diffusivity. The Raman spectrum results confirmed the presence of a B4C network and G and D bands. The results of the four-point probe method indicated that samples with higher boron incorporation showed the lowest sheet resistance (0.06 ω sq−1), which may be because of the decrease in inter-grain boundaries caused by the larger cluster size. This study suggests that higher boron incorporation in boron carbide nanostructures results in larger crystal clusters, higher thickness and lower film resistivity.


Nano Hybrids ◽  
2016 ◽  
Vol 10 ◽  
pp. 1-13
Author(s):  
M.S. Shamsudin ◽  
S.J. Fishlock ◽  
M. Rusop ◽  
S.M. Sanip ◽  
Suan Hui Pu

Graphene has attracted wide interest across a range of applications due to its electrical, mechanical and optical properties. The use of a low-cost, table-top chemical vapour deposition system to deposit few-layer graphene onto copper is reported in this work. Characterisation of the graphene is performed using Raman spectroscopy and atomic force microscopy. The results show that few-layer graphene can be deposited at 1000 °C using CH4 as a carbon precursor, and 5% H2, 95% N2 forming gas as a diluent. The effects of deposition temperature, deposition time, and forming gas addition on graphene film quality was studied experimentally. An increase in graphene quality was observed when forming gas was added during deposition.


Carbon ◽  
2015 ◽  
Vol 94 ◽  
pp. 386-395 ◽  
Author(s):  
Robert L. Harniman ◽  
Oliver J.L. Fox ◽  
Wiebke Janssen ◽  
Sien Drijkoningen ◽  
Ken Haenen ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document