Strain-induced degradation and recovery of flexible NbO_x-based threshold switching device

We investigate the functionality of NbO_x-based selector devices on a flexible substrate. It was observed that the failure mechanism of cyclic tensile strain is from the disruption of atom arrangements, which essentially led to the crack formation of the film. When under cyclic compressive strain, buckling delamination of the film occurs as the compressed films have debonded from their neighboring layers. By implementing an annealing process after the strain-induced degradation, recovery of the device is observed with reduced threshold and hold voltages. The physical mechanism of the device is investigated through Poole-Frenkel mechanism fitting, which provides insights into the switching behavior after mechanical strain and annealing process. The result demonstrates the potential of the NbO_x device in flexible electronics applications with a high endurance of up to 10⁵ cycles of cyclic bending strain and the recovery of the device after degradation.