Combined auxiliary electrode and reflective bank for three-dimensional QLED pixel

A top emitting quantum dot light emitting diode (QLED) apparatus for an emissive display device having a plurality of sub-pixels separated by a bank structure, with each of the plurality of sub-pixels having an emissive region, the top emitting QLED apparatus comprising:

• a plurality of emissive layers, each disposed in the emissive region between a plurality of first electrodes and a second electrode;
• the plurality of first electrodes comprising a reflective metal, individually separated by the bank structure;
• the second electrode comprising a transparent conductive electrode and an auxiliary electrode;
• the bank structure comprising a plurality of sloped portions surrounding each emissive region,
• wherein the auxiliary electrode comprises a reflective conductive metal configured to cover the plurality of sloped portions,
• each of the plurality of sloped portions is configured at an angle, such that the auxiliary electrode reflects internally reflected light out of each sub-pixel in a viewing direction, and
• at least a portion of the transparent conductive electrode is positioned between the sloped portion and the auxiliary electrode.

A top emitting quantum dot light emitting diode (QLED) apparatus for an emissive display device sub-pixel, with at least one bank structure defining an emissive region of the emissive display device sub-pixel, the top emitting QLED apparatus comprising:

• a bottom substrate layer, with the at least one bank structure deposited on the bottom substrate layer;
• a plurality of reflective metal bottom electrodes deposited on the bottom substrate layer, and separated by the at least one bank structure;
• an emissive layer deposited in an emissive region between each of the plurality of reflective metal bottom electrodes and a top electrode layer;
• the top electrode layer comprising a transparent conductive electrode covering the at least one bank structure and the emissive region, and an auxiliary electrode covering only the at least one bank structure;
• the at least one bank structure comprising a sloped portion surrounding each emissive region,
• wherein the auxiliary electrode comprises a highly reflective metal configured to cover the sloped portion,
• at least one portion of the transparent conductive electrode that covers the sloped portion is thinner than other portions of the transparent conductive electrode that cover each emissive region,
• the sloped portion is configured at an angle, such that the auxiliary electrode reflects internally reflected light out of the emissive display device sub-pixel in a viewing direction, and
• the at least one portion of the transparent conductive electrode is positioned between the sloped portion and the auxiliary electrode.