[OPTICAL REVIEW Vol. 13, No. 4 (2006) 222-224]
© 2006 The Optical Society of Japan

Near-Field Evaluation of a Quantum Size Effect in Self-Aligned GaN Whiskers Fabricated Using Photochemical Etching

Kokoro KITAMURA1,*, Takashi YATSUI2 and Motoichi OHTSU1,2

1School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
2Solution-Oriented Research for Science and Technology (SORST), Japan Science and Technology Agency, 687-1 Tsuruma, Machida, Tokyo 194-0004, Japan

(Received November 1, 2005; Accepted December 16, 2005)

We fabricated nanoscale GaN whiskers using photochemical etching. The fabricated GaN whiskers were conjugated and aligned perpendicular to the incident light polarization used for photochemical etching in a self-assembling manner. Their far-field photoluminescence spectra exhibited a blue-shifted photoluminescence peak at 3.60 eV. Near-field photoluminescence spectra of individual GaN whiskers were obtained, for the first time. The evaluation of the near-field spectra identified several peaks from individual whiskers, corresponding to a diameter range of 5–10 nm, and revealed a stepwise change in the diameter along the axis of individual whisker.

Key words: photochemical etching, quantum size effect, whisker, near-field photoluminescence, nanophotonic device

*E-mail: kitamura@nanophotonics.t.u-tokyo.ac.jp