Optical Imaging of CdSe Nanowires with Nanoscale Resolution

Abstract

Down to the wire: High‐resolution photoluminescence (PL) and Raman images of CdSe nanowires were obtained using tip‐enhanced near‐field optical microscopy. They show that the optical properties of the CdSe nanowires vary significantly within a few nanometers leading to strong spatial fluctuations in both PL intensities and energies (see picture).

Tip-enhanced Raman spectroscopy: principles and applications

“…Marquestaut et al studied isolated GaN nanowires, and reported that the near-field enhancement factor depends on the symmetry of the specific vibrational mode [103]. Böhmler et al were able to image single CdSe nanowires using tip-enhanced Raman and PL spectroscopy, thus differentiating the PL energy emission of nanowires with different diameters [104]. Finally, Ogawa et al reported a nanoscale TERS mapping of a single Ge nanowire, and estimated the fraction of crystalline and amorphous content of Ge [105].…”

Tip-enhanced Raman scattering—Targeting structure-specific surface characterization for biomedical samples

“…Controlling polarization on the silicon surface in order to get rid of the background noise from the confocal volume has also been demonstrated and resulted in improved TERS quality [135][136][137]. Other semiconductor materials like GaN [138,139], Ge-, CdSe-nanowire [140,141] have also been probed by TERS. At spatial resolution b 35 nm, variations in crystalline properties were observed, and for semiconductor nanowires, local mapping of the chemical composition, strain, and charge distribution were done.…”

Characterization of semiconductor materials using synchrotron radiation-based near-field infrared microscopy and nano-FTIR spectroscopy

“…Under optimized conditions the illuminated tip acts as an antenna that confines the incident electric field around the tip-apex, thus providing a nanoscale light source for high-resolution imaging. Depending on the wavelength of the incident photons and by analyzing the scattered light with a spectrometer system, sample properties in the visible [9][10][11][12][13][14][15], IR [16][17][18][19][20], and THz [21][22][23][24][25][26] regime can be investigated with the additional benefit of a significantly improved spatial resolution. For wavelengths in the IR regime this technique has already been applied to many different sample systems, e.g.…”