The Laboratory of Optical Spectroscopy/LABONIT was built in 2015 as part of the LABONIT project. The LABONIT project is focused on the development and research of monocrystalline heterostructures of thin layers of nitride semiconductors suitable for luminescence applications with an emphasis on fast or highly efficient scintillators (for use in eg scanning electron microscopy or computed tomography).
For the preparation of quality samples is always necessary a rapid characterization of heterostructures prepared within the same laboratory, as a part of the project was therefore to build a laboratory for the diagnostics and characterization of prepared nitride nanoheterostructures. The basic characteristic of such structures is the description of their chemical composition, material structure and defects. It was with this objective that Confocal Raman and luminescence spectrometer LabRAM HR Evolution was acquired (Figure 1), enabling the use of spectral methods with high spatial and spectral resolution in the temperature range of liquid He to room temperature. It also enables 2D and 3D imaging using optical confocal microscope, which facilitates and accelerate the quality of the prepared structure evaluation, how is required by technologists (Figure 2).
The spectrometer is equipped with two excitation lasers (He- Cd laser, 325 nm and SHG Nd:YAG, 532 nm) and two CCD detectors covering the spectral range of 220-1100 nm. Combination of the Raman and luminescence spectroscopy with confocal microscopy allows measurements at the spatial resolution better than one micrometre, with a high spectral resolution, and with 3D mapping determination of chemical depth profile and chemical composition. This device allows to characterize nitrides immediately after their production. The results of the characterization are used to study the physical properties of new nitride heterostructures and as feedback to improve the technology of prepared structures.