Improved Epitaxy of AlN Film for Deep‐Ultraviolet Light‐Emitting Diodes Enabled by Graphene

Abstract

The growth of single‐crystal III‐nitride films with a low stress and dislocation density is crucial for the semiconductor industry. In particular, AlN‐derived deep‐ultraviolet light‐emitting diodes (DUV‐LEDs) have important applications in microelectronic technologies and environmental sciences but are still limited by large lattice and thermal mismatches between the epilayer and substrate. Here, the quasi‐van der Waals epitaxial (QvdWE) growth of high‐quality AlN films on graphene/sapphire substrates is reported and their application in high‐performance DUV‐LEDs is demonstrated. Guided by density functional theory calculations, it is found that pyrrolic nitrogen in graphene introduced by a plasma treatment greatly facilitates the AlN nucleation and enables fast growth of a mirror‐smooth single‐crystal film in a very short time of ≈0.5 h (≈50% decrease compared with the conventional process), thus leading to a largely reduced cost. Additionally, graphene effectively releases the biaxial stress (0.11 GPa) and reduces the dislocation density in the epilayer. The as‐fabricated DUV‐LED shows a low turn‐on voltage, good reliability, and high output power. This study may provide a revolutionary technology for the epitaxial growth of AlN films and provide opportunities for scalable applications of graphene films.

Vapor‐phase growth of high‐quality wafer‐scale two‐dimensional materials

“…For example, a small amount of oxygen is proposed to reduce the nucleation density of MoS 2 and prevent MoO 3 from being poisoned during the growth, and thus prolongs the lifetime of the MoO 3 precursors and enables the growth of large MoS 2 domains . On the other hand, we can utilize the as‐grown single‐crystal graphene as an ideal buffer layer in the epitaxial growth of other 2D materials . Recently, the epitaxy growth of high‐quality AlN film on single‐crystal graphene has been reported .…”

“…40 On the other hand, we can utilize the as-grown single-crystal graphene as an ideal buffer layer in the epitaxial growth of other 2D materials. 16,102,103 Recently, the epitaxy growth of high-quality AlN film on single-crystal graphene has been reported. 16 Further work is required for the synthesis of various high-quality wafer-scale 2D materials.…”

“…16,102,103 Recently, the epitaxy growth of high-quality AlN film on single-crystal graphene has been reported. 16 Further work is required for the synthesis of various high-quality wafer-scale 2D materials.…”

“…Their practical applications in high‐performance electronics and optoelectronics, such as touch screen, radio frequency devices, photovoltaic devices, solar cell, and so on, are hampered by their poor crystalline quality and limited size. Wafer‐scale and high‐quality 2D materials with few or even without grain boundaries will exhibit excellent electronic performance with high charge mobility, and low interface scattering, which is beneficial in modern electronics . Therefore, routes toward the synthesis of high‐quality (especially single‐crystal) wafer‐scale 2D materials that are compatible with current semiconductor microfabrication processes are essential for exploring the full potential of them in the practical applications.…”

“…Wafer-scale and high-quality 2D materials with few or even without grain boundaries will exhibit excellent electronic performance with high charge mobility, and low interface scattering, which is beneficial in modern electronics. 5,[10][11][12][13][14][15][16][17][18] Therefore, routes toward the synthesis of high-quality (especially single-crystal) wafer-scale 2D materials that are compatible with current semiconductor microfabrication processes are essential for exploring the full potential of them in the practical applications.…”