Role of oxygen vacancies in visible emission and transport properties of indium oxide nanowires

Author： Gali Pradeep Kuo Fang-Ling Shepherd Nigel Philipose U

ISSN： 0268-1242

Source： Semiconductor Science and Technology, Vol.27, Iss.1, 2012-01, pp. : 15015-15019

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Abstract

We report on the effect of oxygen vacancies on the defect-related emission and the electronic properties of In₂O₃ nanowires. The nanowires were synthesized by vapor phase transport and had diameters ranging from 80–100 nm and lengths over 10–20 μm, with a growth direction of [0 0 1]. The as-grown nanowires connected in an FET type of configuration show n-type conductivity, which is ascribed to the presence of intrinsic defects like oxygen vacancies in the nanowire. The resistivity, transconductance, field effect mobility and carrier concentration of the In₂O₃ nanowires were determined to be 1.82 × 10⁻² Ω cm, 11.2 nS, 119 cm² V⁻¹ s⁻¹ and 4.89 × 10¹⁷ cm⁻³, respectively. The presence of oxygen vacancies was also confirmed by photoluminescence measurements, which show a strong UV emission peak at 3.18 eV and defect peaks in the visible region at 2.85 eV, 2.66 eV and 2.5 eV. We present a technique of post-growth annealing in O₂ environment and passivation with (NH₄)₂S to reduce the defect-induced emission.