Epitaxially grown semiconducting hexagonal boron nitride as a deep ultraviolet photonic material

Abstract

Hexagonal boron nitride (hBN) has emerged as an important material for various device applications and as a template for graphene electronics. Low-dimensional hBN is expected to possess rich physical properties, similar to graphene. The synthesis of wafer-scale semiconducting hBN epitaxial layers with high crystalline quality and electrical conductivity control has not been achieved but is highly desirable. Large area hBN epitaxial layers (up to 2 in. in diameter) were synthesized by metal organic chemical vapor deposition. P-type conductivity control was attained by in situ Mg doping. Compared to Mg-doped wurtzite AlN, which possesses a comparable energy band gap (∼6 eV), dramatic reductions in Mg acceptor energy level and P-type resistivity (by about six to seven orders of magnitude) have been realized in hBN epilayers. The ability of conductivity control and wafer-scale production of hBN opens up tremendous opportunities for emerging applications, ranging from revolutionizing p-layer approach in III-nitride deep ultraviolet optoelectronics to graphene electronics.

Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys

“…Carbon to boron (C:B) ratio is varied from ∼8 to 80 for a C 3 H 8 flow rate from 0.5 sccm to 5 sccm. Figure 2(a) shows a representative X-ray diffraction (XRD) θ -2θ scan of a h-(BN) 1-x (C 2 ) x sample with x = 0.032 revealing a lattice constant of c = 6.70 Å, which closely matches with a value of c = 6.67 Å for hexagonal BN (h-BN) epilayers grown at the same temperature 15,16 and also with that of graphite ( Fig. 1(a)).…”

Nature of exciton transitions in hexagonal boron nitride

“…[7][8][9][10] Epitaxial h-BN layers with high optical qualities can be achieved, 7,20 but these materials generally lack the intrinsic FX transitions above 5.7 eV due to the presence of native and point defects. 7,20 Most recent studies have suggested that the D-series emission lines are due to the recombination of excitons bound to deep acceptors formed by carbon impurities occupying the nitrogen sites, and h-BN epilayers exhibiting pure intrinsic FX emission can be obtained by growing the materials under high ammonia flow rates. 21 However, the detailed features of the FX transitions in h-BN epilayers are distinctly different from those in h-BN bulk crystals, 21 which is what remains to be investigated and understood.…”

“…With an energy bandgap around 6.5 eV, h-BN is emerging as an important semiconductor material. [3][4][5][6][7] With its unique physical properties including high temperature and chemical stability, h-BN has potential applications in high temperature/power electronic device applications. P-type conductivity seems to be more easy to realize in h-BN than in AlN, which reveals the potential of h-BN for deep UV emitter and detector applications.…”

“…P-type conductivity seems to be more easy to realize in h-BN than in AlN, which reveals the potential of h-BN for deep UV emitter and detector applications. 7,8 With its large thermal neutron cross-section, h-BN is also a promising material for realizing high efficiency and low cost solid-state neutron detectors. 9,10 Our knowledge concerning the band structure and optical properties of h-BN is limited.…”

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

“…21,22 Different forms of physical vapor deposition (PVD), such as pulsed laser deposition, 23 and reactive magnetron sputtering, 24 have also been used for h-BN thin film growth. While these studies exhibit the progress being made in h-BN growth, a single scalable synthesis method which combines highcrystalline quality with absolute thickness control remains elusive.…”