Large-Area Monolayer Hexagonal Boron Nitride on Pt Foil

Abstract

Hexagonal boron nitride (h-BN) has recently been in the spotlight due to its numerous applications including its being an ideal substrate for two-dimensional electronics, a tunneling material for vertical tunneling devices, and a growth template for heterostructures. However, to obtain a large area of h-BN film while maintaining uniform thickness is still challenging and has not been realized. Here, we report the systematical study of h-BN growth on Pt foil by using low pressure chemical vapor deposition with a borazine source. The monolayer h-BN film was obtained over the whole Pt foil (2 × 5 cm(2)) under <100 mTorr, where the size is limited only by the Pt foil size. A borazine source was catalytically decomposed on the Pt surface, leading to the self-limiting growth of the monolayer without the associating precipitation, which is very similar to the growth of graphene on Cu. The orientation of the h-BN domains was largely confined by the Pt domain, which is confirmed by polarizing optical microscopy (POM) assisted by the nematic liquid crystal (LC) film. The total pressure and orientation of the Pt lattice plane are crucial parameters for thickness control. At high pressure (∼0.5 Torr), thick film was grown on Pt (111), and in contrast, thin film was grown on Pt (001). Our advances in monolayer h-BN growth will play an important role to further develop a high quality h-BN film that can be used for vertical tunneling, optoelectronic devices and growth templates for a variety of heterostructures.

Centimeter-sized epitaxial h-BN films

“…Generally, a precipitation-driven growth is expected to be strongly affected by the change in cooling rate, while a surface-mediated growth would be minimally affected. 35,36 In our case, Figure 3c shows that the film thickness, uniformity, and crystallinity were nearly identical for both fast and slow cooling, which indicates that a surface-mediated growth was more likely. This is presumably attributed to the low dissolution rate of other reactants into the Ni(111) facet owing to its low surface energy.…”

Self‐Aligned Single‐Crystalline Hexagonal Boron Nitride Arrays: Toward Higher Integrated Electronic Devices

“…Because of its various extraordinary properties, such as high electrical resistance, chemical stability, and mechanical strength and hardness, [ 8,9 ] atomically smooth surface free of dangling bonds and charge traps, [ 10 ] and only 1.7% lattice mismatch to graphene, [ 11 ] h-BN can be served as more suitable dielectric substrate for fi eld effect transistors than traditional insulated substrate of SiO 2 /Si. [10][11][12][13][14] Previous reports have shown considerable improvement in the preparation of h-BN on metal substrates, such as Cu, [ 9,[15][16][17][18][19][20][21][22][23][24] Ni, [ 25,26 ] Pt, [27][28][29] Ru, [ 30 ] and Co [ 31 ] via the chemical vapor deposition (CVD). By using the continuous single-layer h-BN fi lm as back gate dielectric, the electronic performance of graphene and graphene-like materials were obviously improved.…”

Synthesis of atomically thin hexagonal boron nitride films on nickel foils by molecular beam epitaxy

“…Chemical vapor deposition (CVD) is the most thoroughly explored method for the growth of h-BN films. The synthesis of mono-and few-layer h-BN by CVD on catalytic single-or polycrystalline transition metals such as Ni, [14][15][16][17] Cu, 18 and Pt 19,20 has been reported.…”