On the high-energy electron beam irradiation-induced defects in Cu₂SnSe₃ system: an effort towards modifying the structure, microstructure, and thermoelectric transport

We present report on modulating thermoelectric transport in Cu₂SnSe₃ system via irradiating high-energy electrons of energy of about 8 MeV. Electrical transport is investigated at near room to mid-temperature regime (300–700 K). A smooth transition from degenerate to non-degenerate type of conductivity is observed in all the samples, which indicates the injection of minority carriers with ionisation of defects at high temperatures. Defects created through the knock-on displacement of the constituent atoms is successful in promoting the power factor in the material. Cu₂SnSe₃ irradiated with 50 kGy is found to achieve highest power factor of 228 µW/mK² at 700 K, which is nearly 20% higher than the power factor of pristine material at the same temperature.