%0 Journal Article
%A Alagha, S.
%A Heedt, S.
%A Vakulov, Daniil
%A Mohammadbeigi, F.
%A Kumar, E Senthil
%A Schäpers, Thomas
%A Isheim, D.
%A Watkins, S. P.
%A Kavanagh, K. L.
%T Electrical properties of lightly Ga-doped ZnO nanowires
%J Semiconductor science and technology
%V 32
%N 12
%@ 1361-6641
%C Bristol
%I IOP Publ.
%M FZJ-2017-08539
%P 125010 -
%D 2017
%X We investigated the growth, crystal structure, elemental composition and electrical transport characteristics of ZnO nanowires, a promising candidate for optoelectronic applications in the UV-range. Nominally-undoped and Ga-doped ZnO nanowires were grown by metal-organic chemical vapor deposition. Photoluminescence measurements confirmed the incorporation of Ga via donor-bound exciton emission. With atom-probe tomography we estimated an upper limit of the Ga impurity concentration (${10}^{18}\,{\mathrm{cm}}^{-3}$). We studied the electrical transport characteristics of these nanowires with a W-nanoprobe technique inside a scanning electron microscope and with lithographically-defined contacts allowing back-gated measurements. An increase in apparent resistivity by two orders of magnitude with decreasing radius was measured with both techniques with a much larger distribution width for the nanoprobe method. A drop in the effective carrier concentration and mobility was found with decreasing radius which can be attributed to carrier depletion and enhanced scattering due to surface states. Little evidence of a change in resistivity was observed with Ga doping, which indicates that the concentration of native or background dopants is higher than the Ga doping concentration.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000414194400003
%R 10.1088/1361-6641/aa91ef
%U https://juser.fz-juelich.de/record/841495