Interface-Induced Seebeck Effect in PtSe₂/PtSe₂ van der Waals Homostructures

Abstract

The Seebeck effect refers to the production of an electric voltage when different temperatures are applied on a conductor, and the corresponding voltage-production efficiency is represented by the Seebeck coefficient. We report a Seebeck effect: thermal generation of driving voltage from the heat flowing in a thin PtSe2/PtSe2 van der Waals homostructure at the interface. We refer to the effect as the interface-induced Seebeck effect. By exploiting this effect by directly attaching multilayered PtSe2 over high-resistance PtSe2 thin films as a hybridized single structure, we obtained the highly challenging in-plane Seebeck coefficient of the PtSe2 films that exhibit extremely high resistances. This direct attachment further enhanced the in-plane thermal Seebeck coefficients of the PtSe2/PtSe2 van der Waals homostructure on sapphire substrates. Consequently, we successfully enhanced the in-plane Seebeck coefficients for the PtSe2 (10 nm)/PtSe2 (2 nm) homostructure approximately 42% compared to that of a pure PtSe2 (10 nm) layer at 300 K. These findings represent a significant achievement in understanding the interface-induced Seebeck effect and provide an effective strategy for promising large-area thermoelectric energy harvesting devices using two-dimensional transition metal dichalcogenide materials, which are ideal thermoelectric platforms with high figures of merit.

Observation of a Strong Decoupling Phenomenon in Pt/Si Hybrid Structures for In-Plane Thermoelectric Properties

“…Under steady-state conditions, we measured the in-plane Seebeck voltage difference (Δ V ∥ ), as shown in Figure d. S ∥ was then determined from the slope of the measured Δ V ∥ and Δ T ∥ in the transverse direction …”

“…S ∥ was then determined from the slope of the measured ΔV ∥ and ΔT ∥ in the transverse direction. 31 To ensure the reliability of the in-plane Seebeck coefficient results for the Pt/Si hybrid structure in our CAU-SYS (Figure 2a,d), we performed the same measurements on the constantan alloy (Cu55−Ni45 wt %) with a commercial equipment system (ZEM-3, ULVAC Riko, Inc., shown in Figure 2e). In the ZEM-3 system, a sample was set in a vertical position between the upper and lower blocks in the heating furnace to evaluate the TE Seebeck coefficient and electrical conductivity of bulk or thin films (Figures 2e and S1b) using the direct current steady-state method.…”

Enhanced Transverse Seebeck Coefficients in 2D/2D PtSe2/MoS2 Heterostructures Using Wet-Transfer Stacking

“…Detailed transverse Seebeck coefficient measurements for pure 2D films and 2D/2D multilayered structures can be found in our previously published report. 13 The temperature gradient was applied using a strain gauge from left to right (i.e., transverse direction). Wettransferred 2D and 2D/2D TMDC both have the following sample sizes (3 mm × 7 mm = width × length).…”

“…Figure 2a shows the measured TE voltage difference in the x-axis direction by applying a temperature gradient along the samples using a strain gauge heater. 13 To ensure the in-house Seebeck coefficient measurement system (i.e., the Chung-Ang University (CAU)-system) reliability for 2D TMDC films, we performed the same measurements on constantan alloy (Cu55−Ni45 wt %) as a reference sample using a commercial system (ZEM-3, ULVAC Riko, Inc.). Figure 2b confirms that the CAU-system achieved acceptable reliability.…”

Phase Change Material (PCM) Composite Supported by 3D Cross-Linked Porous Graphene Aerogel

“…The thermoelectric power generator (TEG) is composed of working materials to induce electron movement [3,4]. The TEG with PN junctions is an effective device to generate induced electrical energy under the temperature variation of the functional device by the Seebeck effect [5,6]. Long-term temperature variation leads to usable pyro-to-electrical conversion to provide large external energy.…”