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Abstract Van der Waals interactions in 2D materials have enabled the realization of nanoelectronics with high‐density vertical integration. Yet, poor energy transport through such 2D–2D and 2D–3D interfaces can limit a device's performance due to overheating. One long‐standing question in the field is how different encapsulating layers (e.g., contact metals or gate oxides) contribute to the thermal transport at the interface of 2D materials with their 3D substrates. Here, a novel self‐heating/self‐sensing electrical thermometry platform is developed based on atomically thin, metallic Ti3C2MXene sheets, which enables experimental investigation of the thermal transport at a Ti3C2/SiO2interface, with and without an aluminum oxide (AlOx) encapsulating layer. It is found that at room temperature, the thermal boundary conductance (TBC) increases from 10.8 to 19.5 MW m−2K−1upon AlOxencapsulation. Boltzmann transport modeling reveals that the TBC can be understood as a series combination of an external resistance between the MXene and the substrate, due to the coupling of low‐frequency flexural acoustic (ZA) phonons to substrate modes, and an internal resistance between ZA and in‐plane phonon modes. It is revealed that internal resistance is a bottle‐neck to heat removal and that encapsulation speeds up the heat transfer into low‐frequency ZA modes and reduces their depopulation, thus increasing the effective TBC.
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Ultra‐High Interfacial Thermal Conductance via Double hBN Encapsulation for Efficient Thermal Management of 2D Electronics
Abstract Heat dissipation is a major limitation of high‐performance electronics. This is especially important in emerging nanoelectronic devices consisting of ultra‐thin layers, heterostructures, and interfaces, where enhancement in thermal transport is highly desired. Here, ultra‐high interfacial thermal conductance in encapsulated van der Waals (vdW) heterostructures with single‐layer transition metal dichalcogenides MX2(MoS2, WSe2, WS2) sandwiched between two hexagonal boron nitride (hBN) layers is reported. Through Raman spectroscopic measurements of suspended and substrate‐supported hBN/MX2/hBN heterostructures with varying laser power and temperature, the out‐of‐plane interfacial thermal conductance in the vertical stack is calibrated. The measured interfacial thermal conductance between MX2and hBN reaches 74 ± 25 MW m−2K−1, which is at least ten times higher than the interfacial thermal conductance of MX2in non‐encapsulation structures. Molecular dynamics (MD) calculations verify and explain the experimental results, suggesting a full encapsulation by hBN layers is accounting for the high interfacial conductance. This ultra‐high interfacial thermal conductance is attributed to the double heat transfer pathways and the clean and tight vdW interface between two crystalline 2D materials. The findings in this study reveal new thermal transport mechanisms in hBN/MX2/hBN structures and shed light on building novel hBN‐encapsulated nanoelectronic devices with enhanced thermal management.
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- PAR ID:
- 10402854
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- Volume:
- 19
- Issue:
- 12
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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