Size, shape, and temperature dependence of the phonon relaxation dynamics of CdSe nanocrystals

From the perspective of bond order-length-strength correlation, we have formulated the Raman phonon relaxation dynamics of CdSe nanocrystals in terms of the length and energy response of the representative bond for all of the entire specimen to the change of crystal shape, size, and the heating conditions. In addition to quantification of the bond length, bond energy, atomic cohesive energy, thermal expansion coefficient, and average coordination numbers of CdSe nanostructures in various shapes, consistency between theory predictions and measurements clarifies that the bond relaxation due to heating and bond-order reduction is responsible for the frequency shift of the CdSe lattice vibration.