Memory diodes with nonzero crossing

Memristors combine switching, memory, and rectification functions in two-terminal nanoelectronic devices. The theory says that their current-voltage (I-V) characteristics cross over at the zero crossing point (I = V = 0), and the results reported hitherto conform to this theorem. Here, we extend the family of memristive devices, adding memory diodes (memdiodes) comprising SrTiO ₃ pn junctions that display unique combination of rectification, hysteresis, and nonzero crossing. Reverse bias polarization gives rise to a nonzero open circuit voltage that persists after the junction is disconnected from the external circuit. This opens up an opportunity for a new type of nonvolatile memories.