We report an investigation of the temperature and carrier concentration dependent thermoelectric behavior of Bi2Se3 single layers based on a combination of experimental data, calculated transport function and electronic structure in light of Boltzmann transport theory and the first-principle. When the carrier concentration is fixed at 3.24 x 10(18)cm(-3), the maximal value of the thermoelectric figure of merit (ZT) is 19 at 900 K, while considering the anisotropy, the higher ZT = 25 can be achieved along xx direction. When the carrier concentration increases to 4 x 10(19)cm(-3), the maximal value of ZT is 38 at 900 K, while considering the anisotropy, the higher ZT = 72 can be achieved along yy direction at carrier concentration of 5.2 x 10(19)cm(-3). Compared with the experimental data, we find that our calculated results agree with experimental data, indicating that our calculations are reliable and reasonable. As more 2D materials have been fabricated besides graphene, our investigation would be important to provide a new strategy to explore high efficiency thermoelectric materials. (C) 2014 Elsevier B. V. All rights reserved.