Spatially-resolved photoluminescence measurements by scanning near-field optical microscope (SNOM)
- Unit: Faculty of Physics
- Keywords: Spatially-resolved photoluminescence, scanning near-field optical microscope, SNOM, semiconductors, semiconductor compounds
Scanning near-field optical microscope (SNOM) is used to study spatial distribution of photoluminescence. The SNOM probe with the aperture smaller than the wavelength is placed in contact with the sample.
The photoluminescence is excited through the aperture. SNOM can simultaneously measure surface morphology and spatial distribution of photoluminescence.
A He-Cd laser (λexc=442 nm) or a laser diode (λexc=405 nm) can be used as photoluminesce excitation source. Photoluminescence can be registered by photomultiplier tube or CCD camera.
Optical spatial resolution of SNOM is 100 nm. It can resolve surface roughness of 200 nm. The maximum area of single measurement is 80×80 µm2. Luminescence can be detected in 350-850 nm spectral range. All the measurements are performed at room temperature.
Application. Measurements of semiconductor materials. Semiconductor and semiconductor compounds industry.