Electroluminescent devices and their manufacture

A method of fabricating an electroluminescent device, the method comprising:

• forming a support layer having a plurality of recesses on a substrate;
• fabricating an electrically conductive region on the substrate in a second recess of the plurality of recesses, wherein the electrically conductive region is formed with electrically conductive protuberances;
• fabricating a first light emissive structure on a substrate, the first light emissive structure comprising:
• organic light emissive material;
• a first electrode layer underlying the organic light emissive material;
• and a second electrode layer overlying the organic light emissive material in a first recess of the plurality of recesses, the second electrode layer and the organic light emissive material extending to the second recess, wherein the first and second electrode layers are adapted to supply charge carriers into the organic light emissive material to cause the organic light emissive material to emit light and the electrically conductive region underlies the first light emissive structure such that the electrically conductive protuberances extend through the thickness of the organic light emissive material, the second electrode layer is electrically connected to the electrically conductive protuberances, and the organic light emissive material partially covers the electrically conductive protuberances;
• fabricating a second light emissive structure, wherein for the second light emissive structure, a first electrode layer underlying an organic light emissive material is connected to the electrically conductive region which underlies the first light emissive structure and is located in said second recess such that the first and second light emissive structures are electrically connected in series.

An electroluminescent device comprising:

• a substrate;
• a support layer having a plurality of recesses and being disposed on the substrate;
• an electrically conductive region on the substrate in a second recess of the plurality of recesses, wherein the electrically conductive region is formed with electrically conductive protuberances;
• a first light emissive structure on a substrate, the first light emissive structure comprising:
• organic light emissive material;
• a first electrode layer underlying the organic light emissive material;
• and a second electrode layer overlying the organic light emissive material in a first recess of the plurality of recesses, the second electrode layer and the organic light emissive material extending to the second recess, wherein the first and second electrode layers are adapted to supply charge carriers into the organic light emissive material to cause the organic light emissive material to emit light and the electrically conductive region underlies the first light emissive structure such that the electrically conductive protuberances extend through the thickness of the organic light emissive material, the second electrode layer is electrically connected to the electrically conductive protuberances, and the organic light emissive material partially covers the electrically conductive protuberances;
• and
• a second light emissive structure, wherein for the second light emissive structure, a first electrode layer underlying an organic light emissive material is connected to the electrically conductive region which underlies the first light emissive structure and is located in said second recess such that the first and second light emissive structures are electrically connected in series.