Piezoelectricity in three-dimensional carbon allotropes studied by first-principles calculations

Researches on carbon materials have shown significant progress recently, which reveal that carbon can form many structures. Along with low-dimensional structures, three-dimensional carbon allotropes have been studied actively. Up to now, at least 822 three-dimensional carbon allotropes have been proposed and some have been synthesized. Despite their immense diversity of structures, the piezoelectric properties of these carbon allotropes have barely been studied. In the present work, we used first-principles calculations to study their piezoelectric response and elastic properties. We find that most of their calculated piezoelectric stress components are between 0.01 and 0.15 C/m(2), and some of them exhibit strong piezoelectric coupling. The largest component is 1.03 C/m(2), sixfold as that of Quartz (0.171 C/m(2)). Accordingly, the largest piezoelectric strain component reaches 3.9 pC/N. These results show that three-dimensional carbon allotropes can be used in active sensors, actuators, and other useful devices.