Electroluminescent display device

A matrix display device having organic electroluminescent layers, successively comprising:

• a substrate;
• a first electrode, to serve as a control electrode having a structure forming a display matrix;
• a first light-emitting assembly comprising at least one first organic electroluminescent layer;
• a second light-emitting assembly comprising at least one second organic electroluminescent layer;
• a second electrode, having opposite polarity to said first electrode, the second electrode being at least partially transparent with respect to light emitted by said at least one first organic electroluminescent layer and said at least one second organic electroluminescent layer,
• wherein:
• a product of a mean refraction index of said at least one first organic electroluminescent layer and said at least one second organic electroluminescent layer, and a distance between a surface opposite the substrate of said first electrode and a surface at the substrate side of said second electrode is between 155 nm and 180 nm,
• a distance between a surface opposite the substrate of said first electrode and a surface opposite the substrate of said at least one first organic electroluminescent layer is between 0.35 times and 0.45 times a distance between a surface opposite the substrate of said first electrode and a surface at the substrate side of said second electrode,
• a distance between a surface opposite the substrate of said first electrode and a surface opposite the substrate of said at least one second organic electroluminescent layer is between 0.8 times and 0.9 times the distance between a surface opposite the substrate of said first electrode and a surface at the substrate side of said second electrode,
• said first light-emitting assembly and said second light-emitting assembly are separated by a first multi-stack functional layer, each layer in the first multi-stack to perform at least one of:
• (i) hole blocking and electron transport, (ii) electron transport, (iii) electron injection, (iv) hole injection, (v) hole transport, (vi) electron blocking and hole transport,
• said first organic electroluminescent layer and said first electrode are separated by a second multi-stacked functional layer, each layer in the second multi-stack to perform at least one of:
• (i) electron blocking and hole transport, (ii) hole injection, (iii) hole transport,
• wherein said matrix display device successively comprises:
• a substrate;
• a first electrode layer serving as an anode;
• a first hole injection layer having a thickness between 0.4 nm and 1.5 nm;
• a hole transport layer having a thickness between 4 nm and 10 nm;
• a first electron-blocking and hole transport layer having a thickness between 4 nm and 10 nm;
• a first electroluminescent layer having a thickness between 15 nm to 25 nm;
• a first hole-blocking and electron transport layer having a thickness between 3 nm and 7 nm;
• a first electron transport layer having a thickness between 3 nm and 7 nm;
• a second hole injection layer having a thickness between 0.4 nm and 1.5 nm;
• a second hole transport layer having a thickness between 3 nm and 7 nm;
• a second electron-blocking and hole transport layer having a thickness between 4 nm and 10 nm;
• a second electroluminescent layer having a thickness between 15 nm and 25 nm;
• a second hole-blocking and electron transport layer having a thickness between 4 nm and 10 nm;
• a second electron transport layer having a thickness between 3 nm and 7 nm;
• a first electron injection layer;
• and
• a second electrode layer serving as a cathode that is at least partially transparent with respect to light emitted by said first electroluminescent layer and said second electroluminescent layer, the second electrode layer having a thickness between 8 nm and 20 nm.