Nonradiative Relaxation of Charge Carriers in GaN-InN Alloys: Insights from Nonadiabatic Molecular Dynamics

The nonradiative relaxation of charge carriers in GaN and In-doped GaN is investigated using nonadiabatic molecular dynamics. Notable differences in relaxation timescales in these materials are attributed to the density of electronic states and symmetry of the systems. Disperse density of states of the system with In atoms results in stronger coupling of electronic states and faster relaxation. The distribution of intraband gaps was found important for defining the order of slow/fast relaxation phases in multiexponential energy loss kinetics. The role of electronic decoherence has been found to be of great significance. It not only slows down the relaxation kinetics, but also changes the behavior to single-exponential one and emphasizes the role of energy gaps. The qualitative behavior of the computed timescales is in good agreement with available experimental data.