Endurance and yield of polycrystalline and amorphous devices. (a, d) Show the endurance of the HRS and LRS, (b, e) depict the evolution of the switching voltages and (c, f) show the yield of the devices. (a–c) Correspond to polycrystalline devices, while (d–f) correspond to amorphous devices. For every data point 128 devices are taken into account. The error bars denote the standard deviation of the averaged measurement data. The read-out and switching times are equal to 10 µs.