Resistive switching of memristors base on epitaxial structures $p$-Si/$p$-Ge/$n^+$-Si(001) with Ru and Ag electrodes

The electrical parameters of the prototype memristors based on $p$-Si/$p$-Ge/$n^+$-Si(001) epitaxial heterostructures with Ag and Ru electrodes have been studied. The memristors with Ru electrodes demonstrated smaller electroforming voltage and greater ratio of currents in the low and high resistance values as compared to the memristors with Ag electrodes. Also, an inversion of the resistance switching polarity was observed in the memristors with Ru electrodes. Thses effects originate from a higher mobility of Ru$^{3+}$ ions in the threading dislocations in the $p$-Si/$p$-Ge layers due to smaller ion radius.