Optically switchable memory

Apparatus for storing information, comprising:

• at least one first electrode and at least one further electrode;
• at least one region of a first material each region being disposed between, and in electrical connection with, a respective first electrode and a further electrode;
• and
• a plurality of changeable particles, in the first material, that have charge storage capability and at least one electrical property that is reversibly changeable responsive to absorption of incident electromagnetic radiation.

A memory cell, comprising:

• a bit line;
• a word line;
• a bit line electrode;
• a word line electrode;
• and
• an active region between and in electrical connection with the bit line electrode and the word line electrode, wherein an electrical property in the active region that is indicative of a memory cell state is switchable responsive to incident electromagnetic radiation in less than 60 seconds between a first electrical property state and at least one further electrical property state.