title: Conditions for stronger field enhancement of semiconductor bowtie nanoantennas.
abstract: A semiconductor bowtie nanoantenna acts as a high-quality cavity because a strongly enhanced field with a narrow spectral width appears at a nanogap region owing to exciton resonance. We theoretically investigate suitable antenna structures to obtain a strong field enhancement, and the following conditions are found: (i) the antenna structure is long in the direction of light polarization, and (ii) the tip structure near the nanogap is blunt. Condition (ii) is opposite to that for a metallic bowtie nanoantenna because the exciton wave function is distributed to avoid a narrow area near the sharp tip. These conditions are expected to be guidelines for designing efficient semiconductor nanoantennas for various applications.
authors: Mitsuharu
authors: M
authors: Uemoto
authors: Hiroshi
authors: H
authors: Ajiki