Crystal Growth and Thermal Properties of Quasi-One-Dimensional van der Waals Material ZrSe₃

ZrSe₃ with a quasi-one-dimensional (quasi-1D) crystal structure belongs to the transition metal trichalcogenides (TMTCs) family. Owing to its unique optical, electrical, and optoelectrical properties, ZrSe₃ is promising for applications in field effect transistors, photodetectors, and thermoelectrics. Compared with extensive studies of the above-mentioned physical properties, the thermal properties of ZrSe₃ have not been experimentally investigated. Here, we report the crystal growth and thermal and optical properties of ZrSe₃. Millimeter-sized single crystalline ZrSe₃ flakes were prepared using a chemical vapor transport method. These flakes could be exfoliated into microribbons by liquid-phase exfoliation. The transmission electron microscope studies suggested that the obtained microribbons were single crystals along the chain axis. ZrSe₃ exhibited a specific heat of 0.311 J g^-1 K^-1 at 300 K, close to the calculated value of the Dulong-Petit limit. The fitting of low-temperature specific heat led to a Debye temperature of 110 K and an average sound velocity of 2122 m s^-1. The thermal conductivity of a polycrystalline ZrSe₃ sample exhibited a maximum value of 10.4 ± 1.9 W m^-1 K^-1 at 40 K. The thermal conductivity decreased above 40 K and reached a room-temperature value of 5.4 ± 1.3 W m^-1 K^-1. The Debye model fitting of the solid thermal conductivity agreed well with the experimental data below 200 K but showed a deviation at high temperatures, indicating that optical phonons could substantially contribute to thermal transport at high temperatures. The calculated phonon mean free path decreased with temperatures between 2 and 21 K. The mean free path at 2 K approached 3 μm, which was similar to the grain size of the polycrystalline sample. This work provides useful insights into the preparation and thermal properties of quasi-1D ZrSe₃.