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

Abstract

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 Zr1-xTixS3 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 Zr0.8Ti0.2S3. 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 Zr1-xTixS3 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 Zr0.82Ti0.18S2.86 devices revealed their n-type conductivity and electron mobility of about 2 cm2 V−1 s−1, as well as photoresponse to visible light.