Properties and device performance of BN thin films grown on GaN by pulsed laser deposition

Abstract

Wide and ultrawide-bandgap semiconductors lie at the heart of next-generation high-power, high-frequency electronics. Here, we report the growth of ultrawide-bandgap boron nitride (BN) thin films on wide-bandgap gallium nitride (GaN) by pulsed laser deposition. Comprehensive spectroscopic (core level and valence band x-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Raman) and microscopic (atomic force microscopy and scanning transmission electron microscopy) characterizations confirm the growth of BN thin films on GaN. Optically, we observed that the BN/GaN heterostructure is second-harmonic generation active. Moreover, we fabricated the BN/GaN heterostructure-based Schottky diode that demonstrates rectifying characteristics, lower turn-on voltage, and an improved breakdown capability (∼234 V) as compared to GaN (∼168 V), owing to the higher breakdown electrical field of BN. Our approach is an early step toward bridging the gap between wide and ultrawide-bandgap materials for potential optoelectronics as well as next-generation high-power electronics.

Non‐Linear Optics at Twist Interfaces in h‐BN/SiC Heterostructures

“…[48,49] Comparatively, the SHG signal for nanocrystalline h-BN on 4H-SiC is found to be significantly higher (≈25 times) than the film on these substrates (with an effective 𝜒 (2) of ≈0.10 pm V −1 ). [48] We measured the cross-plane thermal conductivity k ⊥ of the film using the optical pump-probe method of frequencydomain thermoreflectance (FDTR) (see Experimental Section). An electro-optic modulator (EOM) induced a sinusoidal intensity modulation on the pump, 488 nm continuous wave laser (from a signal generated by the lock-in amplifier), creating a periodic heat flux on the sample surface.…”

“…We also measured the SHG for h‐BN films grown on sapphire and GaN substrates (Figure S7, Supporting Information), on which films are either single‐crystalline (on sapphire) or fully disordered (on GaN). [ 48,49 ] Comparatively, the SHG signal for nanocrystalline h‐BN on 4H‐SiC is found to be significantly higher (≈25 times) than the film on these substrates (with an effective χ (2) of ≈0.10 pm V −1 ). [ 48 ]…”

“…[ 48,49 ] Comparatively, the SHG signal for nanocrystalline h‐BN on 4H‐SiC is found to be significantly higher (≈25 times) than the film on these substrates (with an effective χ (2) of ≈0.10 pm V −1 ). [ 48 ]…”

Single-Photon Emission from Point Defects in Hexagonal Boron Nitride Induced by Plasma Treatment

“…Previous studies have reported that the damage threshold in graphene and h-BN under ion irradiation is dependent on their number of layers. ,, The structural damage in h-BN can lead to the longitudinal optical (LO) phonon mode (E 1u ) at 1609 cm –1 becoming Raman-active by symmetry breaking, − which can be used to characterize the degree of damage of h-BN . To further reveal the relationship between the production of quantum emitters and the defects/layers of h-BN flakes, Raman mappings of the E 1u peak intensity (the integral intensity between 1570 and 1650 cm –1 ) were acquired from the corresponding h-BN flakes.…”

β-Ga2O3-Based Heterostructures and Heterojunctions for Power Electronics: A Review of the Recent Advances

“…Recently, Baskaran et al [127] investigated an AlN/β-Ga 2 O 3 high-electron-mobility transistor (HEMT) on a SiC substrate for power converters and RF applications. Similar to AlN, BN is emerging as a UWBG material with a bandgap of ~6.0 eV and a critical field of ~10 MV/cm [128][129][130]. However, BN predominantly functions as a dielectric material rather than a semiconductor.…”