Thermoelectric power factor of pure graphene

Thermoelectric power factor (PF) of ultra - pure single layer graphene is investigated over a wide temperature range 6 < T< 300 K. Assuming e lectrons to be scattered by in - plan e longitudinal acoustic phonons , we present numerical results o f PF as function of temperature and carrier concentration, n s . We find PF to increase w ith increase in temperature. The role and importance of electrical conductivity and the two components of thermopower , namely , diffusion and drag, are discussed. A nonlinear temperature dependent contribution of the diffus ion component is noticed at lower temperatures. PF is found to decrease with increase in n s .