1 research outputs found
Controlled Synthesis of AlN/GaN Multiple Quantum Well Nanowire Structures and Their Optical Properties
We report the controlled synthesis of AlN/GaN multi-quantum
well
(MQW) radial nanowire heterostructures by metal–organic chemical
vapor deposition. The structure consists of a single-crystal GaN nanowire
core and an epitaxially grown (AlN/GaN)<sub><i>m</i></sub> (<i>m</i> = 3, 13) MQW shell. Optical excitation of individual
MQW nanowires yielded strong, blue-shifted photoluminescence in the
range 340–360 nm, with respect to the GaN near band-edge emission
at 368.8 nm. Cathodoluminescence analysis on the cross-sectional MQW
nanowire samples showed that the blue-shifted ultraviolet luminescence
originated from the GaN quantum wells, while the defect-associated
yellow luminescence was emitted from the GaN core. Computational simulation
provided a quantitative analysis of the mini-band energies in the
AlN/GaN superlattices and suggested the observed blue-shifted emission
corresponds to the interband transitions between the second subbands
of GaN, as a result of quantum confinement and strain effect in these
AlN/GaN MQW nanowire structures