{\it Ab initio} Simulation of Silver Transport in Ge_xSe_1-x: Ag

Abstract

In this paper, we present models of Ge-Se glasses heavily doped with Ag obtained from {\it ab initio} simulation and study the dynamics of the network with an emphasis on the motion of Ag$^+$ ions. The models are analyzed with partial pair correlation functions, static structure factors and novel wavelet techniques. The electronic properties are characterized by the electronic density of states and analysis of specific electronic eigenstates. As Ag content increases, the optical band gap increases. Ag diffusion is observed directly from thermal simulation. The most diffusive Ag$^+$ ions move preferentially through low density regions of the network and the existence of well-defined trapping centers is confirmed. Preliminary information about temperature dependence of trapping and release is provided.