In this paper we present the impact of Sb doping of the GeS2 electrolyte in W/GeS2/Ag based conductive bridge random access memory (CBRAM) on the memory performance. In particular, the CBRAM resistance window, R-ON and R-OFF values versus programming current, power consumption and reliability are analyzed in depth. We demonstrated that the Sb concentration governs the optimal operating conditions. In particular, high Sb doping allows low programming current operation (suitable for low power applications), while low Sb content improves the R-OFF/R-ON ratio (needed in particular for nonvolatile field-programmable gate array applications). Finally, we observed that the high temperature retention could be improved by increasing the Sb doping. This result was interpreted by means of ab initio calculations, indicating that Sb reduces the dissolution rate of the Ag-based conductive filament in the electrolyte. (C) 2014 Elsevier B.V. All rights reserved.