Gallium Nitride Nanocrystal Spectroscopic Properties using Diamondoids Structures

Abstract

In the current work, we study the electronic structure, Fourier Transform Infrared (FTIR), and Raman spectra of GaN diamondoids as a function of particle size and shape, using density functional theory (DFT). We calculated the vibrational spectra of GaN and analyzed them with respect to mass, force constant, and intensity of vibration. Since the size and shape of diamondoids vary among the nanoparticles, we compared them using the tetrahedral angles and bond lengths. The results show that the bond length strongly depends on the shape of the diamondoid molecules. The bond length was also found to increase as the number of cages increased. The total energy as well as the energy gap decrease as the size of nanocrystal clusters increases. These trends might persist at the level of bulk properties because surface effects are negligible in diamondoids