Controllable anisotropic thermoelectric properties in 2D covalent organic radical frameworks

By combining the density functional theory with the Boltzmann transport equation, thermoelectric properties of graphphenyl-based materials are investigated. The results show that anisotropic thermoelectric properties can be realized by breaking symmetry and twisting the phenyl ring. The ZT values reach 1.4 in both p- and n-type thermoelectric materials at room temperature. In addition, the thermoelectric properties of these materials can be further promoted by rotating the phenyl ring. These results demonstrate that these materials have excellent thermoelectric performance, two orders of magnitude greater than that of graphene, and have a wide range of suitable working temperatures. This work provides a way to optimize the thermoelectric performance of two-dimensional conjugated organic radical frameworks and provides theoretical support for the design of electrodes and thermoelectric components made of this organic material.