Amorphous Framework in Electrodeposited CuBiTe Thermoelectric Thin Films with High Room-Temperature Performance

• Published in: ACS applied electronic materials Vol. 3; no. 4; pp. 1794 - 1803
• Main Authors: Padmanathan, N, Lal, Swatchith, Gautam, Devendraprakash, Razeeb, Kafil M
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 27.04.2021
• Subjects: ternary alloy; electroplating; nano-precipitates; thermoelectrics; codeposition; power factor; amorphous thin films
• ISSN: 2637-6113; 2637-6113
• DOI: 10.1021/acsaelm.1c00063

Bismuth telluride-based alloys are the most efficient thermoelectric materials near room temperature and widely used in commercial thermoelectric devices. Nevertheless, their thermoelectric performance needs to be improved further for wide-scale implementation either as a thermoelectric generator or cooler. Here, we propose a simultaneous codeposition of CuBiTe thin films and their phase transition strategy via the traditional electrodeposition process. With just 13 atom % Cu doping, crystalline-to-amorphous phase transformation resulted for the electroplated CuBiTe alloy. A close look at the alloy composition revealed spike-shaped nanocrystalline Bi2Te3 embedded in the CuBiTe amorphous matrix. Our result shows an exceptionally high power factor (3.02 mW m–1 K–2), which comes from the enhanced Seebeck coefficient (−275 μV K–1) and high electrical conductivity (3.99 × 104 S m–1) of CuBiTe films. Therefore, it can be suggested that the adopted strategy to form a unique nanocrystallite-embedded amorphous framework provides a platform to develop next-generation high-performance thermoelectric materials with an extraordinary power factor.