Optimization of thermoelectric power factor of (013)-oriented Ag2Se films via thermal annealing

Thermally evaporated Silver Selenide thin films were time annealed at 210 °C for different soaking periods in vacuum. Annealed films were found to be (013) oriented while as-deposited film was oriented along (121) direction. An appreciable value of Seebeck coefficient (-123 μV/K) was obtained at room temperature for 1.5 hour duration of time annealing. A high power factor of 1.1 mW/mK2 was achieved due to the combined effect of (013) orientation, enhanced mobility and carrier filtering. Such high power factor was achieved with relatively lower contribution of electronic thermal conductivity. Stability of best sample was tested by acquiring measurements again after 3 months. Thus, stable Ag2Se films with promising power factor at room temperature were produced by optimizing the time annealing process.