Controlled Synthesis and Structural Tuning of Re-Doped Tin Selenide Single Crystals via Direct Vapour Transport Technique

Abstract

Layered IV–VI semiconductors such as SnS, SnSe, GeS, and GeSe are known for their orthorhombic crystal structures composed of biplanar atomic layers aligned perpendicular to the c-axis. In the present study, single crystals of Re-doped tin selenide, SnSeRex (x = 0, 0.1, 0.2, 0.3, 0.4), were successfully grown using the Direct Vapour Transport (DVT) method in a custom-designed two-zone horizontal furnace. Energy Dispersive X-ray Analysis (EDAX) was employed to verify the elemental composition and ensure stoichiometric incorporation of rhenium. Structural characteristics of the synthesized crystals were thoroughly investigated using X-ray Diffraction (XRD). All samples maintained an orthorhombic crystal symmetry, indicating structural stability across the doping range. The effects of increasing Re concentration on lattice parameters and crystallinity are discussed, offering insight into the tunability of SnSe-based materials through controlled doping.