Open Access

ARTICLE

Enhancement of Thermoelectric Properties in N-Type and P-Type Ag–Te Nanocomposites via Stirring-Assisted Hydrothermal Synthesis

Donghyeon Lee^#, Jiu Kim^#, Yong-Wook Jeong^#, Miso Shin, Yong Jin Jeong^*

Department of Materials Science and Engineering, Korea National University of Transportation, Chungju, Republic of Korea

* Corresponding Author: Yong Jin Jeong. Email:
# These authors contributed equally to this work

Chalcogenide Letters 2026, 23(2), 1 https://doi.org/10.32604/cl.2026.077885

Received 18 December 2025; Accepted 03 February 2026; Issue published 28 February 2026

Abstract

Silver tellurides (Ag–Te) are promising low-temperature thermoelectric materials because their transport properties can be tuned by subtle compositional variations and nanostructuring. Here, we report a stirring-assisted hydrothermal route that enables controlled synthesis of n-type and p-type Ag–Te nanostructures by adjusting the Ag:Te precursor ratio and hydrodynamic conditions. Samples with Ag:Te ratios of 2:1 (Ag2/Te1) and 1:2 (Ag1/Te2) were synthesized at 120°C for 12 h, varying the stirring speed from 0 to 2000 rpm. X-ray diffraction confirms Ag₂Te as the dominant phase for Ag2/Te1 across all conditions, while Te-rich Ag1/Te2 forms a composite mainly consisting of Te and Ag-deficient Ag_5−xTe₃. For morphology control, the stirring speed significantly alters the microstructural network of the Ag–Te. Moderate stirring (~500 rpm) promotes an interconnected nanowire/nanorod network, whereas higher stirring speeds introduce morphological disruption and secondary phases. Finally, room-temperature transport measurements show that 500 rpm maximizes the power factor for both conduction types: 207.31 μW/mK² for n-type Ag₂Te and 95.83 μW/mK² for p-type Te/Ag_5−xTe₃. This work suggests that controlling the molar ratio of precusors and hydrodynamics during synthesis is a critical factor in optimizing the thermoelectric efficiency of silver tellurides.

---

Keywords

---