@article{7f383571a4e84d149086a61da1a36501,
title = "Rapid Stoichiometry Control in Cu2Se Thin Films for Room-Temperature Power Factor Improvement",
abstract = "Cu2Se thin films provide a promising route toward relatively safe, sustainable and solution processed thermoelectric (TE) modules in contrast to more expensive and toxic materials currently on the market such as Bi2Te3. Cu2Se is known in the TE community for its high performance at high temperature and has recently attracted attention from its large theoretically predicted figure of merit at room temperature. Unfortunately, one of the main limitations encountered so far in Cu2Se thin films is that the carrier concentrations are not optimized for TE operation after solution processing. In this work, we conduct a comprehensive study of the structural, optical, and TE properties of Cu2Se thin films and demonstrate that nonoptimized carrier concentrations in these films lead to observations of poor performance at room temperature. Through a simple soaking procedure in a Cu+ ion solution for only a few minutes, we demonstrate a 200-300% increase in power factor. This soaking process pushes the carrier concentration of the Cu2Se thin film toward its optimal value for TE operation and marks the highest TE performance for any solution processed Cu2Se thin film at room temperature thus far. If the performance can be further optimized at room temperature, Cu2Se thin films will be the material of choice to utilize in TE modules for powering miniature electronics and sensors, which has been an increasingly popular and rapidly expanding market.",
keywords = "carrier concentration, inorganic, p-type, stoichiometry control, thermoelectric, thin films",
author = "Scimeca, {Michael R.} and Fan Yang and Edmond Zaia and Nan Chen and Peter Zhao and Gordon, {Madeleine P.} and Forster, {Jason D.} and Liu, {Yi Sheng} and Jinghua Guo and Urban, {Jeffrey J.} and Ayaskanta Sahu",
note = "Funding Information: A.S. and M.R.S. thank the Tandon School of Engineering at New York University for financial support through start-up funds. This work was partially performed at the Molecular Foundry, Lawrence Berkeley National Laboratory along with the Advanced Light Source and was supported by the Department of Energy, Office of Science, Office of Basic Energy Sciences, Scientific User Facilities Division of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. E.Z. and M.P.G. gratefully acknowledge the National Science Foundation for fellowship support under the National Science Foundation Graduate Research Fellowship Program. We also gratefully acknowledge support for instrument use, scientific and technical assistance from the NYU Shared Instrumentation Facility through the Materials Research Science and Engineering Center (MRSEC) and MRI programs of the National Science Foundation under Award numbers DMR-1420073 and DMR-0923251, the Imaging and Surface Science Facilities of Advanced Science Research Center at the Graduate Center of CUNY, and FY{\textquoteright}s start-up support from the Stevens Institute of Technology. Finally, M.R.S. would like to thank the National Science Foundation for support under Award 1809064. Funding Information: A.S. and M.R.S. thank the Tandon School of Engineering at New York University for financial support through start-up funds. This work was partially performed at the Molecular Foundry, Lawrence Berkeley National Laboratory along with the Advanced Light Source and was supported by the Department of Energy, Office of Science Office of Basic Energy Sciences, Scientific User Facilities Division of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. E.Z. and M.P.G. gratefully acknowledge the National Science Foundation for fellowship support under the National Science Foundation Graduate Research Fellowship Program. We also gratefully acknowledge support for instrument use, scientific and technical assistance from the NYU Shared Instrumentation Facility through the Materials Research Science and Engineering Center (MRSEC) and MRI programs of the National Science Foundation under Award numbers DMR-1420073 and DMR-0923251, the Imaging and Surface Science Facilities of Advanced Science Research Center at the Graduate Center of CUNY, and FY's start-up support from the Stevens Institute of Technology. Finally, M.R.S. would like to thank the National Science Foundation for support under Award 1809064. Publisher Copyright: {\textcopyright} Copyright 2019 American Chemical Society.",
year = "2019",
month = feb,
day = "25",
doi = "10.1021/acsaem.8b02118",
language = "English (US)",
volume = "2",
pages = "1517--1525",
journal = "ACS Applied Energy Materials",
issn = "2574-0962",
publisher = "American Chemical Society",
number = "2",
}