Thermoelectric Effect on Linear Array of Graphene-Based Materials Including Fullerene, Twisted Graphene, and Graphene Nanoribbon

Ahmadi, Ramin; Ahmadi, Mohammad Taghi; Sadeghi, Hatef

doi:10.1149/2162-8777/ac6b53

Cited by 2 publications

(1 citation statement)

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“…Some examples include the use of nanoscale junctions, such as molecular electronic systems with high

[ 21 ], or two dimensional materials, such as graphene (see, e.g., [ 22 , 23 , 24 ] and the references therein). However, such systems are difficult to fabricate in practice, and their relatively high figures of merit can only be reached within a very narrow and unstable window of parameters.…”

Section: Introductionmentioning

confidence: 99%

Thermoelectric Response Enhanced by Surface/Edge States in Physical Nanogaps

García‐Suárez

2023

Materials

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Current solid-state thermoelectric converters have poor performance, which typically renders them useless for practical applications. This problem is demonstrated by the small figures of merit of typical thermoelectric materials, which tend to be much smaller than 1. Increasing this parameter is then key for the development of functional devices in technologically viable applications that can work optimally. We propose here a feasible and effective design of new thermoelectric systems based on physical gaps in nanoscale junctions. We show that, depending on the type of features, i.e., the character of surface/edge states, on both sides of the gap, it is possible to achieve high figures of merit. In particular, we show that, for configurations that have localized states at the surfaces/edges, which translate into sharp resonances in the transmission, it is possible to achieve large Seebeck coefficients and figures of merit by carefully tuning their energy and their coupling to other states. We calculate the thermoelectric coefficients as a function of different parameters and find non-obvious behaviors, such as the existence of a certain coupling between the localized and bulk states for which these quantities have a maximum. The highest Seebeck coefficients and figures of merit are achieved for symmetric junctions, which have the same coupling between the localized state and the bulk states on both sides of the gap. The features and trends of the thermoelectric properties and their changes with various parameters that we find here can be applied not only to systems with nanogaps but also to many other nanoscale junctions, such as those that have surface states or states localized near the contacts between the nanoscale object and the electrodes. The model presented here can, therefore, be used to characterize and predict the thermoelectric properties of many different nanoscale junctions and can also serve as a guide for studying other systems. These results pave the way for the design and fabrication of stable next-generation thermoelectric devices with robust features and improved performance.

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“…Some examples include the use of nanoscale junctions, such as molecular electronic systems with high

Section: Introductionmentioning

confidence: 99%