Novel weak anisotropic thermal management material designed based on first principle
By designing a single -layer RUTE2 material with high -crystal thermal guidance and excellent stability, it solves the problem of thermal management of electronic devices in the 5G era and achieves more efficient heat dissipation effects.
Patent Information
- Application Number
- CN202310928223.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-27
- Publication Date
- 2025-01-28
AI Technical Summary
In the 5G era, material failures caused by thermal management problems of electronic devices account for 65%-80% of the total failure efficiency. The existing thermal interface materials have problems with low thermal conductivity and large thickness, making it difficult to meet the high power and high integration. Electronic devices heat dissipation requirements.
The new two -dimensional transition metal sulfide material is designed -a single layer of RUTE2, which is calculated through the first principle that it has a high -crystal heating rate of 49.4 W/MK at room temperature and maintains excellent excellent at 900 K under 900 K under 900 K. Stability.
As a thermal management material, a single layer of RUTE2 can significantly improve the cooling efficiency of electronic devices, reduce contact thermal resistance, and maintain structural stability under high temperature conditions.
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Abstract
Description
Technical Field
[0001] New device invention. Background Art
[0002] Thermal management systems are widely used in various fields such as the national economy and national defense, controlling the dispersion, storage and conversion of heat in the system. Advanced thermal management materials constitute the material basis of thermal management systems, and thermal conductivity is the core technical indicator of all thermal management materials. When microelectronic materials or devices are bonded to each other, the actual contact area is only 10% of the macroscopic contact area, and the rest are gaps filled with air. The thermal conductivity of air is less than 0.03 W / mK, which is a poor conductor of heat, which reduces the scattering efficiency of the system. Filling these gaps with thermal interface materials (TIM) with high thermal conductivity and ductility to establish gapless contact between microelectronic devices and heat sinks can significantly reduce contact thermal resistance.
[0003] Since 5G technology has been fully popularized, consumer electronic products have accelerated their development towards high power, high integration, lightness and intelligence. As indicators such as integration, power density and assembly density continue to rise, while the performance of electronic devices in the 5G era continues to improve, the working power consumption and heat generation have increased sharply. According to statistics, material failure caused by heat concentration in electronic devices accounts for 65%-80% of the total failure rate. In order to avoid device failure caused by overheating, technologies such as thermal grease, thermal gel, graphite thermal conductive sheet, heat pipe and heat spreader (VC) have emerged and continued to evolve. Heat dissipation management has become a "hard demand" for electronic devices in the 5G era. At present, the heat dissipation technologies used in electronic devices mainly include thermal conductive materials such as graphite heat dissipation, metal backplane, frame heat dissipation, thermal conductive gel heat dissipation, and thermal conductive devices such as heat pipes and VC. Among them, thermal conductive gel, thermal conductive grease, graphite sheets and metal sheets are mainly used in small and medium-sized electronic products, while heat pipes and VC are mainly used in medium and large electronic devices such as notebooks, computers, and servers.
[0004] Thermal conductivity and thickness are the core indicators for evaluating heat dissipation materials. Traditional mobile phone heat dissipation materials are mainly thermal interface materials such as graphite sheets and thermally conductive gels, but graphite sheets have relatively low thermal conductivity and thermal interface materials have relatively large thickness. Driven by mobile phone manufacturers, graphene materials continue to make breakthroughs and begin to enter consumer electronics heat dissipation applications; the thickness of heat pipes and VCs continues to decrease, and they begin to penetrate from computers, servers and other fields to the field of smartphones. The thermal conductivity of two-dimensional semiconductors is one of their important phonon properties. Due to the atomically thin monolayer with van der Waals bonds along the out-of-plane direction, the thermal conductivity of 2D semiconductors is usually thickness-dependent in the out-of-plane and in-plane directions. Some 2D semiconductors, such as h-BN, PdSe2, phosphors, and MoS2, have been reported experimentally and theoretically to have thickness-dependent thermal conductivity. For monolayers with in-plane covalent bonds, weak covalent bonds lead to lower in-plane thermal conductivity than graphene. Therefore, various 2D semiconductor materials with different lattice structures and covalent bond strengths produce different thermal conductivity values. High thermal conductivity materials can be used as thermal management materials. In particular, transition metal dichalcogenides (TMDCs) with tunable band gaps and allotropes can have thermal conductivity at different scales for various functional materials. More importantly, they usually have excellent kinetic, thermal, and mechanical energy stability, and have excellent mechanical properties. For example, it is reported that monolayer 1T-ZrSe2 and monolayer 1T-HfSe2 can still maintain structural stability at a high temperature of 900 K. However, the thermal conductivity of monolayer 1T-ZrSe2 and 1T-HfSe2 at room temperature is only 1.2 W / mK and 1.8 W / mK, which is beneficial for thermoelectric applications but not suitable as a thermal management material. At the same time, monolayer WTe2 with an IT' phase structure has the characteristics of zero band gap and is not suitable as a thermal management material. Therefore, if a new TMD two-dimensional thermal management material can be invented, it will greatly promote the solution to the current heat dissipation problem of tiny devices. Summary of the invention
[0005] According to the above-mentioned problems, the present invention designs a new two-dimensional transition metal sulfide: monolayer RuTe2, which has a high lattice thermal conductivity of 49.4 W / mK at room temperature and still has excellent stability at 900 K. Therefore, monolayer RuTe2 is an ideal thermal management material. Our calculations were performed by first-principles calculations in the Vienna Ab Initio Simulation Package (VASP) and the Perdew-Burke-Ernzerhof (PBE) function was applied. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Figure 1 1 and 2 are top and side views of the crystal structure of a single layer of ruthenium ditelluride in the present invention.
[0007] Figure 2This is the energy band structure of the single-layer ruthenium ditelluride in the present invention near the Fermi level.
[0008] Figure 3 is the phonon dispersion relation of the monolayer ruthenium ditelluride in the present invention.
[0009] Figure 4 It is the free energy change curve of the single-layer ruthenium ditelluride at 900 K in the present invention.
[0010] Figure 5 The single layer of ruthenium ditelluride in the present invention is distributed along x and y direction of the lattice thermal conductivity. Single layer
[0011] The monolayer RuTe2 has a 1T' phase structure formed by in-plane chemical coordination distortion. This unique structure gives it many unique optical and electrical properties. Its structure is very stable, and the shortest bond length is only 2.67 angstroms.
[0012] like Figure 1 As shown, monolayer RuTe2 is anisotropic, with significantly different bond lengths and lattice constants in the a-direction and b-direction, which provides a platform for designing anisotropic electronic devices.
[0013] like Figure 2 As shown, the band gap of monolayer RuTe2 is due to the semiconductor properties with a suitable band gap of 0.66 eV, which provides a corresponding platform for further design of high-performance thermal management materials.
[0014] like Figure 3 As shown, the phonon spectrum of monolayer RuTe2 has no imaginary frequency, indicating that it has good dynamic stability and can exist stably.
[0015] like Figure 4 As shown in Figure 3, the free energy curve of monolayer RuTe2 fluctuates only in a small range within 4ps, which means that it can still maintain good structural stability at a high temperature of 900 K.
[0016] like Figure 5 As shown, the monolayer RuTe2 has high lattice thermal conductivity. At room temperature, the monolayer RuTe2 x and y The lattice thermal conductivities in the directions reach 44 W / mK and 47 W / mK, respectively.
Claims
1. Invention of a new thermal management material with 1T' phase structure.
2. Obtain the crystal structure. Through a series of rigorous tests, it was determined that a reliable crystal structure was obtained with a cutoff energy of 550 eV and a k-point of Monkhorst-Pack 15 × 15 × 1. The vacuum interval along the z-axis was set to 20 Å to ignore the interaction between adjacent layers.
3. Obtaining the band structure. Since the spin-orbit coupling effect has a considerable influence on the band structure of two-dimensional transition metal sulfides, the spin-orbit coupling effect is taken into account.
4. Obtain the phonon structure. Use PHONOPY software to expand the crystal structure obtained in S1, and the expansion factor is 6×4×1. Perform VASP calculation on the obtained supercell to obtain the second-order force constant.
5. The equilibrium structures and free energies at high temperatures were calculated by ab initio molecular dynamics (AIMD) method.
6. Obtain the third-order force constants. Use the Thirdorer software to expand S1 to 5×3×1 and consider 8 neighboring atoms to calculate the third-order force constants.