Graphene‐Based Devices for Thermal Energy Conversion and Utilization

Abstract

Thermal energy conversion and utilization of integrated circuits is a very important research topic. Graphene is a new 2D material with superior electrical, mechanical, thermal, and optical properties, which is expected to continue Moore's law and make breakthroughs in the direction of “More than Moore.” Graphene‐based functionalized devices are applied in various aspects, including breakthroughs in thermal devices, due to their high thermal conductivity and thermal rectification. According to the coupling of different physical quantities, graphene‐based thermal devices can be divided into four categories: uncoupled thermal devices, thermoacoustic coupling devices, thermoelectric coupling devices, and thermo‐optical coupling devices. The structure, working mechanism, and performance of these devices are discussed, as well as the coupling methods of physical quantities. Moreover, scale‐up production of graphene and prospect for future graphene‐based thermal devices are summarized. In‐depth study of the development tendency of these graphene‐based thermal devices is expected to contribute to the development of new high‐performance thermal nanoelectronic devices in the future.

Hot carriers in graphene – fundamentals and applications

“…Hot carriers in graphene can give rise to important thermoelectric and thermomagnetic phenomena. [184][185][186][187][188] Arguably, the most prominent among them is the Seebeck effect, which refers to the conversion of a temperature difference ΔT e into an electrical voltage ΔV. According to eqn (2), when J = 0, this conversion is proportional to the Seebeck coefficient, or thermopower, S = −∇V/∇T e .…”

A Review on Graphene-Based Light Emitting Functional Devices

“…Moreover, the electrically biased layered graphene facilitates the accumulation of spatially localized hot electrons (~2,800 K), which makes graphene an ideal material for the application of light-emitting device at the nanoscale. In addition, the tunability of broad-spectrum emission can be attained by manipulating the strong interference effect; particularly, the interference effect in an ultra-thin and flat layer of graphene could allow the realization of unique flexible, thin, transparent and large-scale display modules [ 61 ]. In the case of freely suspended graphene, the issues of the dominant heat dissipation through the substrate can be overcome.…”

“… Graphene-based light-emitting functional devices, where the emission radiation from graphene has been ascribed to thermal, electroluminescence, and plasmons assisted emissions [ 58 , 60 , 61 , 62 , 63 ]. …”

“…( d ) The emission spectra of single and multi-layered graphene, calibrated with the back body at 673 K, where the peak emission was approximately 4 um and the large deep trench at 4.2 µm was ascribed to the CO 2 absorption. ( e , f ) shows the measured and simulated spectra with a dash [ 61 ].…”

2D Nanomaterials for Effective Energy Scavenging

“…However, the thermoelectric device performance is closely dependent in accordance with the thermoelectric figure of merit ZT where ZT = S 2 σ / k total ; S denotes the Seebeck coefficient, σ symbolizes the electric conductivity, and k total refers to the total thermal conductivity [ 99 ]. In thermal energy scavenging, there can be four types of TE devices, which include the uncoupled thermal, thermoacoustic coupled, thermoelectric coupled, and the thermal and optical coupled devices; these are based on different materials, techniques for their synthesis, and application requirements [ 100 ]. A schematic of the mechanism of a thermoelectric generator is shown in Fig.…”