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

TL;DR

This study uses ab initio simulations to model silver-doped Ge-Se glasses, analyzing their structure, electronic properties, and Ag$^+$ ion diffusion behavior, revealing insights into trapping centers and temperature effects.

Contribution

First ab initio models of heavily Ag-doped Ge-Se glasses that analyze structural, electronic, and diffusion properties with novel wavelet techniques.

Findings

Ag content increases optical band gap.

Ag$^+$ ions diffuse through low-density regions.

Trapping centers influence ion mobility.

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.