In this study, chalcogenide material Ge 10 Se 70 Bi 20 thin films have been fabricated utilizing the thermal evaporation technique of bulk samples on glass substrates. After that, the original Ge 10 Se 70 Bi 20 thin films irradiated by different types of an ion beam. The compositions of the original film was determined by the Energy Dispersive X-Ray (EDX). X-ray diffraction (XRD) measurements were performed to characterize and examine the induced variations in the structure of Ge 10 Se 70 Bi 20 films after irradiation. From the optical measurements, the absorption edge, bandgap, Urbach energy, Tauc parameter, and extinction coefficient of the unirradiated and irradiated films were determined. In particular, the DC electrical conductivity increased by two orders after the pure film was exposed to an oxygen ion beam. Besides, the activation energy and Mott’s parameters for the original and irradiated Ge 10 Se 70 Bi 20 films were deduced. The reported variations in absorption coefficient, optical bandgap, dc electrical conductivity, and Mott’s parameters propose that the irradiated Ge 10 Se 70 B 20 thin films can be used in important applications, e.g., optical data storage and optoelectronic devices.