Heterojunction device comprising a semiconductor and a resistivity-switching oxide or nitride

A memory cell comprising a heterojunction diode comprising:

• a semiconductor element comprising:
• a first semiconductor layer of heavily doped silicon, germanium, silicon-germanium, or an alloy thereof of a first conductivity type;
• and
• a second semiconductor layer of silicon, germanium, silicon-germanium, or an alloy thereof, the second semiconductor layer above and in contact with the first semiconductor layer, wherein the second semiconductor layer is intrinsic or lightly doped to the first conductivity type;
• and
• a switching element comprising a layer of a conductive binary metal oxide or nitride compound above and in contact with the second semiconductor layer, wherein a p-n junction is formed between the second semiconductor layer and the layer of the conductive binary metal oxide or nitride compound,
• wherein the switching element has a first polarity and the second semiconductor layer has a second polarity opposite the first polarity.