Anti-Stokes Photoluminescence and Enhanced Raman Scattering from InSb Nanodots and Nanowires

InSb nanodots, nanowires and bulk crystals were examined by conventional micro-Raman and scanning near-field optical microscope (SNOM) systems. InSb nanodots and nanowires examined were fabricated on Si substrates by a vapor-transport method using a focused-ion beam(FIB) system[1]. Surprisingly strong anti-Stokes photoluminescence was found from the samples when a high power laser density (up to $\sim $10$^{6}$ W/cm$^{2})$ was used. Drastic decrease of the anti-Stokes luminescence with decreasing the sample temperature suggested that phonon-carrier scattering played an important role. Moreover, enhanced second-order Raman scattering was observed, which depended on both the laser power density and samples. We speculate that the second-order Raman enhancement may be caused by the excitons created by photoirradiation. [1] M. Ishizuka, T. Horiuchi and N. Wada, \textit{Narrow Gap Semiconductors}, edited by J. Kono and J. L\'{e}otin, Taylor {\&} Francis, 2006, p. 125-130.