Thermoelectric Properties of Graphene Through BN-ring Doping: A Theoretical Investigation

Although graphene presents excellent transport properties, its potential for thermoelectric applications is still limited due to its low Seebeck coefficient and high thermal conductivity. Efforts to enhance its thermoelectric properties have involved the usage of carbon-based nanoribbons (Zheng et al., 2012; Hossain et al., 2016) [1,2], strain engineering (Nguyen et al., 2015), and heteroatom co-doping, particularly with nitrogen and/or boron atoms (Wang et al., 2018) [3]. In this work, multiscale simulation approaches combining density functional theory calculations and semi-empirical models are used to investigate the thermoelectric properties of graphene via borazine (B3N3)-ring doping. In particular, the bandgap engineering obtained by this doping technique (Caputo et al., 2022) can separate opposite electron and hole contributions and therefore results in a significant enhancement of the Seebeck effect and, accordingly, of the power factor. The results obtained are not only dependent on the concentration of B3N3 rings but are also notably influenced by their orientation configuration. Furthermore, the effects of distribution and rotational disorders are also considered, clarifying the thermoelectric properties of realistic systems. Lastly, the thermal lattice conductance is estimated revealing a substantial reduction of up to 40% compared to pristine graphene opening up the possibility of enhancing the thermoelectric efficiency of BNC materials. The present theoretical approach highlights how BN-ring doping can refine the thermoelectric properties of graphene, offering a pathway for enhancing its suitability in practical thermoelectric applications.