<p>We examine the effect of irradiation on structural, morphological, and electrical transport properties of Ge₂Sb₂Te₅ (GST) thin films using Ag¹¹⁺ ion irradiation of 140&#xa0;MeV. We thoroughly investigate the effect of ion irradiation on morphology along with structural and electrical transport properties of GST films. Utilizing techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM), we investigated phase transitions and post-irradiation modifications in the crystallinity. The findings demonstrate that ion irradiation significantly modifies phase stability and increases disorder in the microstructure. Notably, larger doses of radiation encourage crystallization and phase segregation, whereas lower amounts strengthen the amorphous state. Current–voltage (I–V) characteristics show a change in the conductive behavior of the films, which may have implications for the improved thermoelectric performance. Here, the study of electrical transport properties is also presented, which shows improvement in electrical applications of GST material with increased irradiation dose. This work explains the possibility of optimizing GST thin films by means of regulated ion irradiation, hence advancing the development of thermoelectric materials.</p>