Switching device

A switching device comprising an electrode-insulator-electrode structure supported on a substrate having a supporting function, said insulator having a periodical layer structure from 10.ANG. to 1000.ANG. in thickness of an organic insulator, one of said electrodes, which is close to said substrate as compared to the other electrode, being selected from a noble metal or an oxide conductor, said layer being a mixed monomolecular film or a mixed monomolecular built-up film of an amphiphilic compound having a hydrocarbon chain or a polymeric compound having a hydrophobic region and a hydrophilic region and a molecule having Pi electron conjugated system said device having a first memorizable electrical state exhibiting a first resistance and a second memorizable electrical state exhibiting a higher second resistance in a voltage region below a first threshold voltage and above a different second threshold voltage, said device being switchable from the first electrical state to the second electrical state upon application of a voltage of one polarity equal to or exceeding said first threshold voltage and switchable from the second electrical state to the first electrical state upon application of an opposite polarity voltage equal to or exceeding the second threshold voltage.

A switching device comprising an electrode-insulator-electrode structure supported on a substrate having a supporting function, said insulator having a periodical layer structure from 10.ANG. to 1000.ANG. in thickness of an insulating or semiconductive organic metal comprising a molecule having Pi electron conjugated system, one of electrodes, which is close to said substrate as compared to the other electrode, being selected from a noble metal or an oxide conductor, and means for applying electrical signals for controlling the switching characteristics of said switching device, said device having a first memorizable electrical state exhibiting a first resistance and a second memorizable electrical state exhibiting a higher second resistance in a voltage region below a first threshold voltage and above a different second threshold voltage, said device being switchable from the first electrical state to the second electrical state upon application of a voltage of one polarity equal to or exceeding said first threshold voltage and switchable from the second electrical state to the first electrical state upon application of an opposite polarity voltage equal to or exceeding the second threshold voltage.

A switching device comprising an electrode-organic insulator-electrode structure supported on a substrate having a supporting function, said organic insulator from 10.ANG. to 1000.ANG. in thickness being formed of a LB film or an organic material having a Pi electron level, one of said electrodes, which is close to said substrate as compared to the other electrode, being selected from a noble metal or an oxide conductor, said device having a first memorizable electrical state exhibiting a first resistance and a second memorizable electrical state exhibiting a higher second resistance in a voltage region below a first threshold voltage and above a different second threshold voltage, said device being switchable from the first electrical state to the second electrical state upon application of a voltage of one polarity equal to or exceeding said first threshold voltage and switchable from the second electrical state to the first electrical state upon application of an opposite polarity voltage equal to or exceeding the second threshold voltage.

A switching method, comprising the steps of:

• (a) providing a device comprising an electrode-organic insulator-electrode structure supported on a substrate having a supporting function, said organic insulator having a periodical structure from 10.ANG. to 1000.ANG. in thickness, said organic insulator comprising a molecule having a Pi electron conjugated system and one of said electrodes, which is close to said substrate as compared to the other electrode, being selected from a noble metal or an oxide conductor, wherein said device having a first memorizable electrical state exhibiting a first resistance and a second memorizable electrical state exhibiting a higher second resistance in a voltage region below a first threshold voltage and above a different second threshold voltage, said device being switchable between said electrical states;
• and
• (b) applying a voltage of one polarity equal to or exceeding a threshold voltage between said electrodes to switch the device to a different electrical state and, optionally, applying a voltage of an opposite polarity equal to or exceeding the other threshold voltage to switch said device to the other electrical state.

A memory device comprising an electrode-insulator-electrode structure supported on a substrate having a supporting function, said insulator having a periodical layer structure from 10.ANG. to 1,000.ANG. in thickness of an organic insulator comprising a molecule having Pi electron conjugated system, one of said electrodes, which is close to said substrate as compared to the other electrode, being selected from a noble metal or an oxide conductor, said device having a first memorizable electrical state exhibiting a first resistance and a second memorizable electrical state exhibiting a higher second resistance in a voltage region below a first threshold voltage and above a different second threshold voltage, said device being switchable from the first electrical state to the second electrical state upon application of a voltage of one polarity equal to or exceeding said first threshold voltage and switchable from the second electrical state to the first electrical state upon application of an opposite polarity voltage equal to or exceeding the second threshold voltage.