Multi-functional spin-caloritronic device based on co-doped zigzag silicene nanoribbon heterojunction

• The proposed work focusses on the spin-caloritronic properties of silicene nanoribbon heterojunction. • The spin degeneracy in zigzag silicene nanoribbons (ZSiNRs) is broken by co-doping the ZSiNR with boron (B) and nitrogen (N) atoms. • The proposed device shows spin transport under the application of a thermal gradient. • The proposed device displays several spin related effects like spin-Seebeck diode effect (SSD), spin filtering effect (SFE), and spin-Seebeck effect (SSE) along with thermal colossal magnetoresistance (CMR) effect. The discovery of graphene has sparked significant interest in two-dimensional (2D) materials within the research community. Graphene’s discovery has led to the exploration of several 2D-materials with varied properties. Silicene, a silicon-based analogue of graphene, is one of the newer 2D-materials. Silicene is a promising material for electronic applications and novel fields like spintronics. In this study, we propose a spin-caloritronic device based on zigzag silicene nanoribbons (ZSiNRs). The device features a heterojunction between two ZSiNRs, one of which is doped with boron (B) and nitrogen (N) atoms. The ZSiNRs’ edges are terminated with hydrogen (H) atoms for both the nanoribbons in the heterojunction. We utilize the density functional theory (DFT) combined with non-equilibrium Green’s function (NEGF) to investigate the thermal-spin transport properties of this device under the influence of a thermal gradient. Notably, the device operates without any external bias, with spin transport driven solely by the thermal gradient. We find that a thermal colossal magnetoresistance (CMR) effect may be produced by modulating thermally generated spin currents by changing the magnetic configuration. Furthermore, the proposed device has superior transport properties, displaying phenomena including the spin-Seebeck diode effect (SSD), spin filtering effect (SFE), and spin-Seebeck effect (SSE). These characteristics position the proposed device as a strong candidate for multi-functional spin-caloritronic applications.