Study mode of growth and characterization of ZrTe5 thin films synthesized using chemical vapor deposition

Three-dimensional quantum Hall effect (QHE) in bulk ZrTe5 has sparked strong interest in realizing QHE in the two-dimensional (2D) limit. Achieving this requires controlled growth of high-quality ZrTe5 thin films, which are promising hosts for quantum spin Hall insulators and next-generation dissipationless electronics. In this work, we investigate the role of growth temperature (TG) and mass flux in the chemical vapor deposition (CVD) growth of ZrTe5 thin films on SiO2/Si substrates. The evolution from kinetically driven growth to thermodynamically stable thin-film formation is governed by factors such as growth temperature, adatom diffusivity, flux ratio, and growth time. Employing a space-confined CVD method, we demonstrate tunable dimensionality from few-layer islands to continuous films within a narrow growth window. Structural and microstructural analyses reveal that higher annealing temperatures enhance crystallinity, while atomic force microscopy provides detailed insights into growth mechanisms under varying conditions. XPS valence band spectra and UV–Visible spectroscopy show that the Fermi level shifts toward the valence band maximum with increasing annealing temperature, indicating p-type carrier dominance. Magnetotransport studies confirm the semiconducting behavior of polycrystalline ZrTe5 films, exhibiting a saturating magnetoresistance of ∼1.21% at 2 K under 7 T. The observed Hall resistance (Rxy) likely originates from nonvanishing intrinsic Berry curvature. These results establish CVD-grown ZrTe5 thin films as a scalable platform for exploring 2D topological phases and their potential in device applications.