Buffer assisted charge generation layer for tandem OLEDs

An active matrix display comprising:

• an array of organic light emitting diode (OLED) pixels, each of the OLED pixels including
• a plurality of OLED sub-pixels, at least one of the OLED sub-pixels having a buffer assisted charge generation layer including
• a junction of p-type doped semiconductor layer and an n-type doped semiconductor layer, and
• a hole buffer layer and an electron buffer layer pair surrounding the junction of the p-type and n-type doped semiconductor layers;
• a first OLED emissive layer and a second OLED emissive layer pair surrounding the buffer assisted charge generation layer;
• and
• a cathode and anode layer pair surrounding the first and second OLED emissive layer pair;
• and
• a driving circuit connected to and configured to provide an energizing signal to each of the plurality of sub-pixels of the array of OLED pixels within the active matrix display;
• wherein the hole buffer layer is between and adjacent to the p-type doped semiconductor layer and one of the first or second OLED emissive layers, and the electron buffer layer is between and adjacent to the n-type doped semiconductor layer and the other of the first or second OLED emissive layers.

A method of fabricating an Organic Light Emitting Diode (OLED) matrix display, comprising:

• forming an array of OLEDs pixels over a substrate, each pixel of the OLED array including a plurality of OLED sub-pixels, wherein at least one sub-pixel of the plurality of OLED subpixels include
• a buffer assisted charge generation layer including
• a p-type electrode layer adjacent an n-type electrode layer, and
• a hole buffer layer and an electron buffer layer surrounding the coupled p-type and n-type electrode layers,
• a first OLED emissive layer and a second OLED emissive layer pair surrounding the buffer assisted charge generation layer, and
• a cathode and anode layer pair surrounding the first and second OLED emissive layers;
• and
• providing a driving circuit connected to and configured to provide an energizing signal to each of the plurality of sub-pixels of the array of pixels within the active matrix display;
• wherein the hole buffer layer is between and adjacent to the p-type doped semiconductor layer and one of the first or second OLED emissive layers, and the electron buffer layer is between and adjacent to the n-type doped semiconductor layer the other of the first or second OLED emissive layers.