Self-assembled Growth of GaN Nanostructures on Flexible Metal Foils by Laser Molecular Beam Epitaxy

Kushvaha, S. S.; Kumar, Mahesh

doi:10.1007/978-981-15-9904-0_5

Cited by 1 publication

(1 citation statement)

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“…Three Raman modes are observed at 529.3, 558.8, and 566.1 cm −1 , which correspond to A 1 (TO), E 1 (TO), and E 2 (High) modes of hexagonal GaN. 19,20 The prominent Raman E 2 (high) peak for all samples at 566.1 cm −1 indicates the good crystalline quality of the GaN grown on Ta foil 21 and is close to the Raman mode of stree-free bulk GaN, i.e., 566.2 cm −1 , 22 which further complements the HRTEM observation. The intensity of the E 2 (high) peak is decreasing for the GaN grown on the nitridated Ta surface, which could be explained based on the decrease in the density of GaN NRs along the c-axis which agrees with the FESEM observations.…”

Section: Resultsmentioning

confidence: 88%

Role of Surface Chemistry of Ta Metal Foil on the Growth of GaN Nanorods by Laser Molecular Beam Epitaxy and Their Field Emission Characteristics

Pradhan,

Tyagi,

Pal

et al. 2024

ACS Appl. Mater. Interfaces

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This study investigates the influence of surface nitridation of Ta metal foil substrates on the growth of GaN nanorods using the laser molecular beam epitaxy (LMBE) technique and the field emission characteristics of the grown GaN nanorod ensemble. Surface morphology examinations underscore the pivotal role of Ta foil nitridation in shaping the dimensions and densities of GaN nanorods. Bare Ta foil fosters the formation of high-density, vertically self-aligned GaN nanorods at a growth temperature of 700 °C. Furthermore, the density of these nanorods is directly related to the duration of Ta foil nitridation, with increased duration leading to a reduced nanorod density. X-ray Photoelectron Spectroscopy (XPS) studies reveal that the transition of the Ta foil surface from tantalum oxide to tantalum nitride during nitridation emerges as a crucial factor influencing GaN nanorod growth. Photoluminescence (PL) spectroscopy at ambient temperature reveals a strong near-band-edge (NBE) emission peak with negligible defect-related peaks, displaying the high optical quality of the GaN nanorods. The highly dense vertically aligned GaN nanorod ensemble growth without Ta prenitridation exhibits the most favorable field emission performance, featuring a turn-on field of 2.1 V/μm, a field enhancement factor of 2480, and a stable long-term operation at the emission current density of 2.26 mA/cm2. This study advances the understanding of the role of the surface chemistry of metal foil in determining GaN nanorod growth and opens up exciting possibilities for tailoring advanced optoelectronic devices for specific application requirements.

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Section: Resultsmentioning

confidence: 88%