Thermodefect voltage in graphene nanoribbon junctions. (11th May 2022)

• Record Type: Journal Article
• Authors: Aydin, Alhun; Sisman, Altug; Fransson, Jonas; Black-Schaffer, Annica M; Dutta, Paramita
• Is Part Of: Journal of physics. Volume 34:Number 19(2022)
• Publication Date: 2022-05-11
• Subjects: thermoelectricity -- graphene -- defect; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ac553b
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Thermoelectric junctions are often made of components of different materials characterized by distinct transport properties. Single material junctions, with the same type of charge carriers, have also been considered to investigate various classical and quantum effects on the thermoelectric properties of nanostructured materials. We here introduce the concept of defect-induced thermoelectric voltage, namely, thermodefect voltage, in graphene nanoribbon (GNR) junctions under a temperature gradient. Our thermodefect junction is formed by two GNRs with identical properties except the existence of defects in one of the nanoribbons. At room temperature the thermodefect voltage is highly sensitive to the types of defects, their locations, as well as the width and edge configurations of the GNRs. We computationally demonstrate that the thermodefect voltage can be as high as 1.7 mV K −1 for 555–777 defects in semiconducting armchair GNRs. We further investigate the Seebeck coefficient, electrical conductance, and electronic thermal conductance, and also the power factor of the individual junction components to explain the thermodefect effect. Taken together, our study presents a new pathway to enhance the thermoelectric properties of nanomaterials.