Effects of Heavy Ion Irradiation on the Thermoelectric Properties of In 2 (Te 1-x Se x ) 3 Thin Films.

Ion irradiation is an exceptionally effective approach to induce controlled surface modification/defects in semiconducting thin films. In this investigation, ion-irradiated Se-Te-based compounds exhibit electrical transport properties that greatly favor the transformation of waste heat into electricity. Enhancements of both the Seebeck coefficient (S) and the power factor (PF) of In 2 (Te 0.98 Se 0.02 ) 3 films under 120 MeV Ni 9+ ion irradiation were examined. The maximum S value of the pristine film was about ~221 µVK -1 . A significantly higher S value of about ~427 µVK -1 was obtained following irradiation at 1 × 10 13 ions/cm 2 . The observed S values suggest the n-type conductivity of these films, in agreement with Hall measurements. Additionally, Ni ion irradiation increased the PF from ~1.23 to 4.91 µW/K 2 m, demonstrating that the irradiated films outperformed the pristine samples. This enhancement in the TE performance of the In 2 (Te 0.98 Se 0.02 ) 3 system is elucidated by irradiation-induced effects that are revealed by structural and morphological studies.