Cascaded light emitting devices based on mixed conductor electroluminescence

A cascaded light emitting device, comprising:

• a split electrode structure formed of a first electrode material, the split electrode structure includes a plurality of electrode portions, an electrical resistance between any pair of electrode portions of the split electrode structure being greater than a split resistance, the plurality of electrode portions including a first electrode portion electrically coupled to a first voltage lead and a second electrode portion electrically coupled to a second voltage lead;
• an opposing electrode formed of a second electrode material;
• and
• at least one electroluminescent layer coupled between the split electrode structure and the opposing electrode, the at least one electroluminescent layer including a mixed conductor that luminesces with a peak wavelength, a total thickness of the at least one electroluminescent layer being such that a resistance across the at least one electroluminescent layer between an electrode portion of the split electrode structure and the opposing electrode is less than half of the split resistance.

A method for driving of an electroluminescent device with an alternating current, the electroluminescent device including a first electrode, a second electrode, and at least one electroluminescent layer coupled between the first electrode and the second electrode, the at least one electroluminescent layer including an mixed conductor, the method comprising the steps of:

• a) biasing the electroluminescent device to generate a polarizing voltage across the at least one electroluminescent layer from the first electrode to the second electrode, the polarization voltage being greater than or equal to a voltage necessary to enhance charge injection into the mixed conductor;
• b) maintaining a potential difference across the at least one electroluminescent layer from the first electrode to the second electrode above an operational voltage for a predetermined luminescence period, the operational voltage being less than or equal to the polarizing voltage and greater than or equal to a voltage necessary to drive electroluminescence in the polarized mixed conductor;
• c) biasing the electroluminescent device to generate the polarizing voltage across the at least one electroluminescent layer from the second electrode to the first electrode;
• d) maintaining the potential difference across the at least one electroluminescent layer from the second electrode to the first electrode above an operational voltage for the predetermined luminescence period;
• and
• e) repeating steps (a), (b), (c), (d), and (e).