Method of designing an OLED display with lifetime optimized primaries

A method of designing an improved color OLED display device, comprising the steps of:

• a) identifying a plurality of different OLED materials having differing chromaticity coordinates, luminance stability over time, and luminance efficiency;
• b) calculating an estimate of display lifetime for a plurality of combinations of the different OLED materials used to produce a pixel having a white point with a defined chromaticity coordinate and luminance;
• c) calculating a figure of merit for the color gamut for each combination;
• and
• d) using an optimization criterion that includes the display lifetime and color gamut figure of merit to select one of the plurality of combinations of OLED materials for use in the display.

A method of determining an optimal combination of OLED emissive materials to be used to construct a plurality of subpixels of different colors in a pixel of a display device, wherein selection of materials are based on the luminance efficiency of the OLED materials, the chromaticity and luminance of a target display white point, and the luminance stability over time of the OLED materials, comprising the steps of:

• a) measuring chromaticity coordinates for a plurality of materials;
• b) selecting aim chromaticity coordinates and luminance of a target display white point;
• c) for a plurality of combinations of the OLED materials,
• i) calculating a required luminance for a subpixel using the chromaticity coordinates of the OLED materials, and the aim chromaticity coordinates and the luminance of the target display white point,
• ii) selecting an initial light emissive area for each subpixel,
• iii) providing an optical transmission factor for each subpixel,
• iv) calculating an actual luminance for each subpixel using the initial areas and optical transmission factors for the subpixel,
• v) determining a functional relationship between current density and luminance output for each subpixel,
• vi) calculating an aim current density for each subpixel,
• vii) determining a functional relationship between current density and a luminance stability over time for each subpixel,
• viii) calculating a lifetime for each subpixel using the aim current density and the luminance stability functions and defining a display lifetime as the minimum subpixel lifetime,
• ix) calculating a figure of merit for the color gamut for each combination;
• d) using an optimization criterion that includes the display lifetime and color gamut figure of merit to select one of the plurality of combinations of OLED materials for use in the display.