Electroluminescent element

An electroluminescent element comprising:

• a pair of electrodes, at least one of which is transparent, disposed on a substrate;
• a luminescent layer having upper and lower surfaces;
• a compound semiconductor layer stacked on at least one of said upper and lower surfaces of said luminescent layer to form a stacked luminescent/compound semiconductor layer;
• and
• insulating layers, at least a first of said insulating layers interposed between a first of said pair of electrodes and said stacked luminescent/compound semiconductor layer and at least a second of said insulating layers interposed between a second of said pair of electrodes and said stacked luminescent/compound semiconductor layer,
• wherein said compound semiconductor layer is selected to have a clamp electric field intensity higher than a clamp electric field intensity of said luminescent layer, and
• wherein the product of a dielectric constant and said clamp electric field intensity of said luminescent layer is larger than the product of a dielectric constant and said clamp electric field intensity of said compound semiconductor layer.

An electroluminescent element comprising:

• a pair of electrodes, at least one of which is transparent, disposed on a substrate;
• a first luminescent layer having upper and lower surfaces;
• a second luminescent layer stacked on either one of said upper and lower surfaces of said first luminescent layer to form stacked luminescent layers;
• and
• insulating layers, at least a first of said insulating layers interposed between a first of said pair of electrodes and said stacked luminescent layers and at least a second of said insulating layers interposed between a second of said pair of electrodes and said stacked luminescent layers,
• wherein said second luminescent layer and said first luminescent layer have different clamp electric field intensities, and
• wherein the product of a dielectric constant and said clamp electric field intensity of said luminescent layer having a lower clamp electric field intensity is larger than the product of a dielectric constant and said clamp electric field intensity of said luminescent layer having a higher clamp electric field intensity.

An electroluminescent element comprising:

• a first electrode formed on a substrate;
• a first insulating layer formed on said first electrode;
• a first luminescent layer formed on said first insulating layer, said first luminescent layer comprising a plurality of pieces arranged such that portions of said first insulating layer are exposed between adjacent ones of said pieces;
• a second luminescent layer comprising stacked layer portions formed on corresponding ones of said pieces of said first luminescent layer and single layer portions formed on corresponding ones of said portions of said first insulating layer exposed between adjacent ones of said pieces;
• a second insulating layer formed on said second luminescent layer;
• and
• a second electrode formed on said second insulating layer,
• wherein said first and second luminescent layers have clamp electric field intensities different from each other so that the product of a dielectric constant and said clamp electric field intensity of said luminescent layer having a lower clamp electric field intensity is larger than the product of a dielectric constant and said clamp electric field intensity of said luminescent layer having a higher clamp electric field intensity.

An electroluminescent element comprising:

• a first electrode formed on a substrate;
• a first insulating layer formed on said first electrode;
• a first luminescent layer formed on said first insulating layer,
• a second luminescent layer formed on said first luminescent layer, said second luminescent layer comprising a plurality of pieces arranged such that single layer portions of said first luminescent layer are exposed between adjacent ones of said pieces and stacked layer portions of said first luminescent layer are in stacked relationship with said second luminescent layer;
• a second insulating layer formed on said second luminescent layer;
• and
• a second electrode formed on said second insulating layer,
• wherein said first and second luminescent layers have clamp electric field intensities different from each other so that the product of a dielectric constant and said clamp electric field intensity of said luminescent layer having a lower clamp electric field intensity is larger than the product of a dielectric constant and said clamp electric field intensity of said luminescent layer having a higher clamp electric field intensity.