Thickness-Dependent In-Plane Thermal Conductivity and Enhanced Thermoelectric Performance in p-Type ZrTe ₅ Nanoribbons

Topological materials attract enormous attention due to their unique physical properties and thermoelectric applications. ZrTe ₅ , a semimetal material, is proposed to be a new topological material and shows interesting thickness-dependent electrical transport properties. Here, the in-plane thermal conductivity and power factor in exfoliated few-layer ZrTe ₅ nanoribbons with different thickness measured using suspended thermal bridge method are reported. A nearly linearly thickness-dependent thermal conductivity κ is observed where thicker nanoribbons present higher thermal conductivity in the temperature range of 100–300 K due to phonon-boundary scattering. More interestingly, the room temperature figure of merit ZT of 140 nm-thick ZrTe ₅ nanoribbon is five times higher than that in bulk ZrTe ₅ , providing superior thermoelectric performance in thinner ZrTe ₅ nanoribbons and revealing the promising prospect of ZrTe ₅ nanoribbons as thermoelectric materials.