N. Dhindsa, A. Chia, J. Boulanger, I. Khodadad, R. LaPierre, J. Walia, S. Saini
University of Waterloo, Canada
pp. 105 - 107
Keywords: gallium arsenide nanowires, nanowire photonics, dry etching
We present highly ordered vertical gallium arsenide (GaAs) nanowires fabricated by dry etching using various metal mask combinations. A great control on the length, diameter, pitch and facet tapering of the nanowires was achieved. Diameters ranging from 30 nm to 250 nm with pitch from 200 nm to 1100 nm and length up to 2 microns were fabricated using this process. The highest diameter to pitch ratio was ∼68%. The reflection measurements were performed on the samples and the diameter dependent strong absorption peaks due to optical modal excitations were observed from the refection measurements. Finite difference time domain (FDTD) analysis was performed to validate the measurements. The modal analysis was done from the same simulations. The hybrid cylindrical waveguide modes as the function of nanowires diameter were identified to be linear. Also the near field coupling between nanowires was absent even at the small pitches. The work done here paves the way towards achieving high efficiency solar cells, lasers, single photon emissions and tunable photodetectors using III–V nanowires.