Synthesis and exfoliation of quasi-1D (Zr,Ti)S₃ solid solutions for device measurements

Transition metal trichalcogenides (TMTCs), such as TiS₃ and ZrS₃, attract growing interest because of their peculiar quasi-one-dimensional (quasi-1D) structure and promising electronic properties. In this study, we investigated Zr_1-xTi_xS₃ solid solutions and demonstrated that they could be prepared through the direct reaction between Zr–Ti alloys and sulfur vapor at 800 °C. We varied the Zr/Ti atomic ratio in the alloys from 80/20 to 20/80 and found that in all cases the resulting solid solution crystals had a composition close to Zr_0.8Ti_0.2S₃. The excessive titanium, if present, formed the secondary TiS₂ phase, which was detected by the powder X-ray diffraction (XRD) analysis and observed in scanning electron microscopy (SEM) images in the form of hexagonal crystals. The Zr_1-xTi_xS₃ solid solutions formed distinct needle-like crystals, whose shape was consistent with the quasi-1D structure of TMTCs. We demonstrated that these crystals could be mechanically exfoliated into thin nanoribbons by an adhesive tape approach and used for device fabrication and electrical measurements. The transport measurements of Zr_0.82Ti_0.18S_2.86 devices revealed their n-type conductivity and electron mobility of about 2 cm² V⁻¹ s⁻¹, as well as photoresponse to visible light.