Growth of boron-doped few-layer graphene by molecular beam epitaxy

Abstract

We investigated the growth of boron-doped few-layer graphene on α-Al2O3 (0001) substrates by molecular beam epitaxy using two different growth approaches: one where boron was provided during the entire graphene synthesis and the second where boron was provided only during the second half of the graphene growth run. Electrical measurements show a higher p-type carrier concentration for samples fabricated utilizing the second approach, with a remarkable modulation in the carrier concentration of almost two orders of magnitude in comparison to the pristine graphene film. The results concerning the influence of the boron flux at different growth stages of graphene on the electrical and physicochemical properties of the films are presented.

Structural Quantification for Graphene and Related Two-Dimensional Materials by Raman Spectroscopy

“…Substitutional doping of graphene, such as nitrogen or boron substitution, acts as a dual effect of charge doping and defects. Consequently, − (i) G band downshifts for low nitrogen doping concentration and then upshifts for higher doping and upshifts for boron doping; (ii) G band stiffens and broadens for both nitrogen and boron doping due to the nonadiabatic removal of the Kohn anomaly and the absence of blockage of decay channels of phonons; (iii) G′ band also stiffens, and the intensity ratio I G′ / I G decreases; (iv) strong D and D′ bands appear. The doping concentration can be quantified by combining the shift of G band frequency and the intensity ratio I D / I G .…”

Metal-Free Synthesis of Boron-Doped Graphene Glass by Hot-Filament Chemical Vapor Deposition for Wave Energy Harvesting

“…Heteroatom doping, which either donates or withdraws free electrons to the graphitic carbon atoms, has been an effective way to endow graphene with tunable and enhanced properties. , Among numerous heteroatoms, boron (B) and nitrogen (N) are ideal candidates owing to their comparable atomic sizes and valence electron numbers with carbon atoms . The N doping can induce the n-type conducting behavior of graphene, which is opposite to the pristine ones that exhibit the weak p-type conduction caused by the surface absorption of oxygen and water vapor from atmosphere . Recently, the improvement of conductivity, catalytic activity, and hydrovoltaic property of graphene glass by N doping has been reported. − Compared to N doping, B doping is an equivalent way to tailor properties of graphene .…”

“…Recently, the improvement of conductivity, catalytic activity, and hydrovoltaic property of graphene glass by N doping has been reported. − Compared to N doping, B doping is an equivalent way to tailor properties of graphene . The B doping induces the p-type conducting behavior of graphene with tunable band gap, modulated work function, and improved chemical activity. − However, unlike N doping, research studies about the preparation of B-doped graphene through the CVD method are still rare. ,, Moreover, the successful fabrication of B-doped graphene glass has not been reported by far.…”

“…28 The N doping can induce the n-type conducting behavior of graphene, which is opposite to the pristine ones that exhibit the weak p-type conduction caused by the surface absorption of oxygen and water vapor from atmosphere. 29 Recently, the improvement of conductivity, catalytic activity, and hydrovoltaic property of graphene glass by N doping has been reported. 30−32 Compared to N doping, B doping is an equivalent way to tailor properties of graphene.…”

Growth of Ordered Graphene Ribbons by Sublimation Epitaxy

“…Due to its unique properties, such as the unusual half-integer quantum Hall effect [1,2] and mass-less Dirac fermion behavior [3,4], graphene has many potential applications in the fields of novel physics, chemistry, optics, and mechanics [5,6], and as realistic technology transfer in the fields of membrane technology [7], energy [8], photodetection [9], and plasmonics [10]. Since the successful preparation of the first stable graphene flake at room temperature by peeling highly oriented pyrolytic graphite (HOPG) [11], people have developed many methods to prepare graphene, including monolayer [12,13], bilayer [14,15], and few-layer graphene [16,17], in the form of powder [18], flake [19], and film [20]. Although intrinsic monolayer graphene is a semimetal without a bandgap, we can open a specific bandgap by patterning graphene into nano-ribbons or coupling graphene with certain substrates [21,22]; bilayer graphene can be operated to have a high on/off ratio, and a bandgap up to hundreds of millielectronvolts controlled by an electronic field, which paves the way for its applications in high performance electronics [23].…”