TY - JOUR
T1 - Improved performance of GaAsSb/AlGaAs nanowire ensemble Schottky barrier based photodetector via in situ annealing
AU - Sharma, Manish
AU - Ahmad, Estiak
AU - Dev, Durjoy
AU - Li, Jia
AU - Reynolds, C Lewis
AU - Liu, Yang
AU - Iyer, Shanthi N
PY - 2019/1/18
Y1 - 2019/1/18
N2 - In this work, we report on the p-i GaAsSb/AlGaAs nanowires (NWs) ensemble device exhibiting good spectral response up to 1.1 μm with a high responsivity of 311 A W-1, an external quantum efficiency of 6.1 104%, and a detectivity of 1.9 × 1010 Jones at 633 nm. The high responsivity of the NWs has been attributed to in situ post-growth annealing of GaAsSb axial NWs in the ultra-high vacuum. The enabling growth technology is molecular beam epitaxy for the Ga-assisted epitaxial growth of these NWs on Si (111) substrates. Room temperature Raman spectra, as well as temperature dependent micro-photoluminescence peak analysis indicated suppression of band tail states and non-radiative channels due to annealing. A similar improvement in in situ annealed p-i GaAsSb NW ensemble with an AlGaAs passivating shell was inferred from a reduction in the Schottky barrier height as well as the NW resistance compared to the as-grown NW ensemble. These results demonstrate in situ annealing of nanowires to be an effective pathway for improving the optoelectronic properties of the NWs and the device thereof.
AB - In this work, we report on the p-i GaAsSb/AlGaAs nanowires (NWs) ensemble device exhibiting good spectral response up to 1.1 μm with a high responsivity of 311 A W-1, an external quantum efficiency of 6.1 104%, and a detectivity of 1.9 × 1010 Jones at 633 nm. The high responsivity of the NWs has been attributed to in situ post-growth annealing of GaAsSb axial NWs in the ultra-high vacuum. The enabling growth technology is molecular beam epitaxy for the Ga-assisted epitaxial growth of these NWs on Si (111) substrates. Room temperature Raman spectra, as well as temperature dependent micro-photoluminescence peak analysis indicated suppression of band tail states and non-radiative channels due to annealing. A similar improvement in in situ annealed p-i GaAsSb NW ensemble with an AlGaAs passivating shell was inferred from a reduction in the Schottky barrier height as well as the NW resistance compared to the as-grown NW ensemble. These results demonstrate in situ annealing of nanowires to be an effective pathway for improving the optoelectronic properties of the NWs and the device thereof.
KW - axial p-i GaAsSb/AlGaAs/GaAs core-shell photodetector
KW - external quantum efficiency
KW - in situ annealing
KW - molecular beam epitaxy
KW - suppression of band tail states
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U2 - 10.1088/1361-6528/aae148
DO - 10.1088/1361-6528/aae148
M3 - Article
C2 - 30212376
SN - 0957-4484
VL - 30
JO - Nanotechnology
JF - Nanotechnology
IS - 3
M1 - 034005
ER -