Electrical and Mechanical Behavior of Chromium Disilicide Thin Films on Polyethylene Terephthalate under Tensile Strain

The present work is dedicated to the mechanical and electrical properties of CrSi2 thin films, deposited on PET substrates, in tensile strains, with a focus on issues concerning crack formation and increased strain-induced resistance degradation. CrSi2 is one of the most important semiconducting materials for flexible electronics, which has excellent thermal stability, high electrical conductivity, and remarkable robustness in various environmental conditions, making it an ideal candidate for wearable and stretchable applications. The tensile testing performed by mechanical testing along with in situ electrical resistance measurement provided quantification of PCER as a function of strain increase, while SEM carried out detailed observations of crack initiation and propagation for 100- and 200-nm CrSi₂ films to gain insight into their structural limits under applied mechanical stress. The thinner films of 100 nm presented faster crack formation and a rapid increase in resistance under smaller strains that caused earlier electrical failure, while in 200 nm films, higher thickness resulted in greater resistance to cracking and more variability in modes of failure. This study presents a novel investigation into the fracture mechanics of CrSi₂ thin films under tensile strain by providing a quantitative comparison between 100 nm and 200 nm thicknesses using in situ electrical resistance monitoring. The findings offer new insights into the critical role of film thickness in delaying crack initiation and mitigating electrical failure, thereby proposing a practical approach for optimizing the mechanical robustness and reliability of CrSi₂-based components in flexible electronic applications. The results strongly highlight the significant role of thickness in enhancing fracture resistance and maintaining electrical stability in CrSi₂ thin films. This finding provides valuable insightinto designing durable CrSi₂-based components in flexible electronic applications where reliability upon mechanical deformation is a prime consideration.