Solid Immersion Lens Microscope for Spectroscopy of Nanostructure Materials

We demonstrate a high-spatial-resolution imaging and spectroscopy tool using a solid immersion lens (SIL), a hemispherical lens made of high refractive index glass (n similar to 2). Photoluminescence (PL) images of single CdSe nanocrystals confirm a numerical aperture enhancement factor of similar to 2, close to the refractive index of the SIL. In particular, a bare-eye observation of PL signals emitted by single nanocrystals with similar to 10 mu m(-2) densities was possible over an similar to 30 mu m diameter region. In addition, the PL spectra of single CdSe nanocrystals were successfully measured at room temperature. Thus, this SIL microscope ensures a simple but powerful method for nanostructure spectroscopy.