Based on the hysteresis characteristics, memory operation tests were performed for the devices with the X-ASiO-PVPNP layers. The writing-once-reading-many (WORM) test showed that both 5 mol.% and 10 mol.% PVP devices properly made proper operations of reading (VG = −1 V and VD = −3 V) after writing (VG = −5 V and VD = −3 V) (see Fig. 5a). However, the 10 mol.% PVP devices showed better WORM characteristics with stable signals. In the case of writing-reading-erasing-reading (WRER) cycle test (Fig. 5b), the 10 mol.% devices exhibited more stable memory functions with clearer drain current difference between reading-1 (R1) after writing (W) and reading-2 (R2) after erasing (E). In contrast, the 5 mol.% devices showed less stable WRER characteristics in the presence of small drain current difference. The superior memory performance of the 10 mol.% PVP devices is also evidenced from the repeated WORM and WRER operations (see Fig. S5). Hence the 10 mol.% PVP devices can be called one of TOMDs with proper memory functions.