Tuning the Structural Phase and Charge Transport in Ge-Doped Ag₂Te Thin Films Prepared by Thermal Evaporation

hussien Aied; Firas A. Najim

doi:10.71229/zfmqvs36

Authors

Hussein H. Kazem Department of Physics, College of Education, University of Al-Qadisiyah, Al-Diwaniyah, Iraq https://orcid.org/0009-0009-5361-1941
Firas A. Najim Al-Qadisiyah University College, of, Al-Diwaniyah, Iraq

DOI:

https://doi.org/10.71229/zfmqvs36

Keywords:

Ge-doped, , Ag2Te thin films, , Electric properties, , Structural characteristics

Abstract

This study examines the effect of the addition of germanium (Ge) on the compositional, morphological, and electrical properties of silver telluride (Ag₂Te) thin films obtained using vacuum thermal evaporation technology. After deposition, the prepared membranes were subjected to a systematic annealing process at a temperature of 150°C to stabilize the monoclinic phase. X-ray diffraction analysis (XRD) confirmed the formation of a high-purity monoclinic structure with a characteristic stress in the crystal lattice caused by the introduction of germanium. The morphological properties of FE-SEM and AFM showed a significant improvement in surface uniformity and grain cohesion in saturated samples. Electrical measurements based on the Hall effect showed a fundamental improvement in charge transfer properties; in particular, a sample saturated with 2% germanium (Ge) demonstrated exceptional carrier mobility of 10.6 × 10³ cm²/V.s and electrical conductivity of 9.80 (Ω.cm)^-1. In addition, measurements of the Seebeck Effect in the temperature range from 295 to 365 K confirmed the conductivity of the P-type of all samples, since the values of the Seebeck coefficient(S) for germanium-saturated membranes ranged from 128 to 145 µV/K. A significant jump in the Seebeck response was observed at a temperature of 354 K for a sample saturated with 4% germanium, indicating improved carrier scattering mechanisms. These results suggest that precise Ge alloying combined with controlled heat treatment provides a reliable strategy for the development of highly efficient Ag₂Te p-type thin films for advanced thermoelectric and electronic applications.

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