The heteroepitaxy of high-quality aluminum nitride (AlN)
with low
stress is essential for the development of energy-efficient deep ultraviolet
light-emitting diodes (DUV-LEDs). In this work, we realize that quasi-van
der Waals epitaxy growth of a stress-released AlN film with low dislocation
density on hexagonal boron nitride (h-BN)/sapphire suffered from high-temperature
annealing (HTA) treatment and demonstrate its application in a DUV-LED.
It is revealed that HTA effectively improves the crystalline quality
and surface morphology of monolayer h-BN. Guided by first-principles
calculations, we demonstrate that h-BN can enhance lateral migration
of Al atoms due to the ability to lower the surface migration barrier
(less than 0.14 eV), resulting in the rapid coalescence of the AlN
film. The HTA h-BN is also proved to be efficient in reducing the
dislocation density and releasing the large strain in the AlN epilayer.
Based on the low-stress and high-quality AlN film on HTA h-BN, the
as-fabricated 290 nm DUV-LED exhibits 80% luminescence enhancement
compared to that without h-BN, as well as good reliability with a
negligible wavelength shift under high current. These findings broaden
the applications of h-BN in favor of III-nitride and provide an opportunity
for further developing DUV optoelectronic devices on large mismatched
heterogeneous substrates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.