Ultra-high power factor of p-type Bi 2 Se 3 for room-temperature thermoelectric applications.

Achieving high zT in n-type and p-type thermoelements in similar compounds is a great challenge for device construction. Herein, we report a high-power factor of 480 μW/mK 2 in Ga and Mn co-doped Bi 2 Se 3 along with a maximum zT of 0.25 at 303 K as a p-type thermoelement. The co-doped Ga and Mn play distinct roles in enhancing the hole concentration to 1.6 × 10 19 cm -3 with a maximized effective mass. In addition, a drastic reduction in lattice thermal conductivity of 0.5 W/mK is attained due to point defects of mass and strain field fluctuation scattering in Bi 2 Se 3 .