Thermoelectric properties of γ-graphyne and its derivatives: First-principles calculations

Two-dimensional thermoelectric materials is of special interest in recent years. Here, we studied the electronic and thermoelectric properties of two semiconducting carbon allotropes, γ-graphyne and its derivative, based on first-principles calculations. The small band gaps and long relaxation times of carriers benefit the thermal transport. We found that the thermoelectric efficiency in both materials is quite large, and reaches the maximum value around 900 K, with carrier concentration in the order of 1021 cm−3. Our research suggests that these two allotropes are promising candidates for the thermoelectric materials applications.