TY - GEN
T1 - The formation of hexagonal-shaped InGaN-nanodisk on GaN-nanowire observed in plasma source molecular beam epitaxy
AU - Ng, Tien Khee
AU - Gasim, Anwar A.
AU - Cha, Dong Kyu
AU - Janjua, Bilal
AU - Yang, Yang
AU - Jahangir, Shafat
AU - Zhao, Chao
AU - Bhattacharya, Pallab
AU - Ooi, Boon S.
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2014/3/8
Y1 - 2014/3/8
N2 - We report on the properties and growth kinetics of defect-free, photoluminescence (PL) efficient mushroom-like nanowires (MNWs) in the form of ~30nm thick hexagonal-shaped InGaN-nanodisk on GaN nanowires, coexisting with the conventional rod-like InGaN-on-GaN nanowires (RNWs) on (111)-silicon-substrate. When characterized using confocal microscopy (CFM) with 458nm laser excitation, while measuring spontaneous-emission at fixed detection wavelengths, the spatial intensity map evolved from having uniform pixelated emission, to having only an emission ring, and then a round emission spot. This corresponds to the PL emission with increasing indium composition; starting from emission mainly from the RNW, and then the 540 nm emission from one MNWs ensemble, followed by the 590 nm emission from a different MNW ensemble, respectively. These hexagonal-shaped InGaN-nano-disks ensembles were obtained during molecular-beam-epitaxy (MBE) growth. On the other hand, the regular rod-like InGaN-on-GaN nanowires (RNWs) were emitting at a shorter peak wavelength of 490 nm. While the formation of InGaN rod-like nanowire is well-understood, the formation of the hexagonal-shaped InGaN-nanodisk-on-GaN-nanowire requires further investigation. It was postulated to arise from the highly sensitive growth kinetics during plasma-assisted MBE of InGaN at low temperature, i.e. when the substrate temperature was reduced from 800 °C (GaN growth) to
AB - We report on the properties and growth kinetics of defect-free, photoluminescence (PL) efficient mushroom-like nanowires (MNWs) in the form of ~30nm thick hexagonal-shaped InGaN-nanodisk on GaN nanowires, coexisting with the conventional rod-like InGaN-on-GaN nanowires (RNWs) on (111)-silicon-substrate. When characterized using confocal microscopy (CFM) with 458nm laser excitation, while measuring spontaneous-emission at fixed detection wavelengths, the spatial intensity map evolved from having uniform pixelated emission, to having only an emission ring, and then a round emission spot. This corresponds to the PL emission with increasing indium composition; starting from emission mainly from the RNW, and then the 540 nm emission from one MNWs ensemble, followed by the 590 nm emission from a different MNW ensemble, respectively. These hexagonal-shaped InGaN-nano-disks ensembles were obtained during molecular-beam-epitaxy (MBE) growth. On the other hand, the regular rod-like InGaN-on-GaN nanowires (RNWs) were emitting at a shorter peak wavelength of 490 nm. While the formation of InGaN rod-like nanowire is well-understood, the formation of the hexagonal-shaped InGaN-nanodisk-on-GaN-nanowire requires further investigation. It was postulated to arise from the highly sensitive growth kinetics during plasma-assisted MBE of InGaN at low temperature, i.e. when the substrate temperature was reduced from 800 °C (GaN growth) to
UR - http://hdl.handle.net/10754/555649
UR - http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2039627
UR - http://www.scopus.com/inward/record.url?scp=84901766888&partnerID=8YFLogxK
U2 - 10.1117/12.2039627
DO - 10.1117/12.2039627
M3 - Conference contribution
SN - 9780819498991
BT - Gallium Nitride Materials and Devices IX
PB - SPIE-Intl Soc Optical Eng
ER -