At the ultra-thin film limit, quantum confinement strongly improves thermoelectric figure of merit in materials such as Sb2Te3 and Bi2Te3. These high quality films have only been realized using well controlled techniques such as molecular beam epitaxy. We report a two fold increase in the Seebeck coefficient for both p-type Sb2Te3 and n-type Bi2Te3 using thermal co-evaporation, an affordable approach. At the thick film limit greater than 100 nm, their Seebeck coefficients are around 100 μV/K, similar to results obtained in other work. When the films are thinner than 50 nm, the Seebeck coefficient increases to about 500 μV/K. With a total Seebeck coefficient ∼ 1 mV/K and an estimate ZT ∼ 2, this pair of materials is the first step to a practical micro-cooler at room temperature.
@article{arxiv.1912.11274,
title = {Enhanced thermoelectricity at the ultra-thin film limit},
author = {Thao T. T. Nguyen and Linh T. Dang and Giang H. Bach and Tung H. Dang and Kien T. Nguyen and Hong T. Pham and Thuat T. Nguyen and Tuyen V. Nguyen and Toan T. Nguyen and Hung Q. Nguyen},
journal= {arXiv preprint arXiv:1912.11274},
year = {2021}
}