Structural and Optical Properties of ZnSe Nanoparticles

We successfully synthesized ZnSe nanoparticles (NPs) by using a hydrothermal method. Careful analyses of X-ray diffraction pattern and high-resolution transmission electron microscopy images showed that the synthesized ZnSe NPs with the size of ˜100 nm and sphere-like morphology crystallized in the zincblende/cubic structure (the F-43m space group). This was also confirmed based upon characteristic vibration modes recorded by using Raman scattering spectroscopy. The study on room-temperature absorption and photoluminescence (PL) spectra proved ZnSe NPs having high crystal quality with the band gap energy E g ≈2.63 eV at 300 K and excitonic emission peaked at ˜2.64 eV (469 nm). Particularly, as studying temperature-dependent PL spectra, we found the shift of the emission peak towards lower energies while the PL intensity decreased when temperature increased from 15 to 300 K. The PL spectral parameters were analyzed by using the Arrhenius and Varshni laws.