Enhancing resistive switching behavior in double perovskites through doping and silver vacancies: A first-principles analysis

Abstract

Double perovskites with formula A₂BB’X₆ offer a broad range of compositions, making them promising for discovering new materials with unique properties, especially for Resistive Random-Access Memory (RRAM) applications. A detailed study of the physical properties of Rb₂XAgCl₆ (X = Sc, Y, In, Ga) double perovskites is performed using PBE-GGA and HSE-06 approximations. To understand the resistive switching mechanisms, the role of doping and V_Ag in these materials is explored by analyzing their electronic properties, including band structure and total density of states. The pristine materials originally had wide band gaps of 3.59 eV and 3.28 eV. Upon substituting Sc and Y with In and Ga using PBE-GGA, these were significantly reduced to 0.96 eV and 0.97 eV, respectively. However, with HSE-06 calculations, the band gaps improved to 3.50 eV and 3.92 eV for Sc and Y materials and 1.49 eV and 1.01 eV for the In and Ga, indicating a notable enhancement in band gap values compared to PBE-GGA. Introducing V_Ag (vacancy of silver) into doped structure further decrease the band gaps to zero, indicating metallic conductivity suitable for resistive switching. The elastic properties confirmed structural stability, even after doping and vacancy creation, maintaining mechanical integrity essential for device durability. Moreover, their optical properties show their potential to absorb significant electromagnetic radiation, enhancing their suitability for advanced memory technologies. The combined properties of these composites demonstrate their suitability for next-generation RRAM devices.