Two‐Color Strip‐Patterned White OLEDs: Tunable Color‐Temperature via Pattern Dimension Control

White light is attained by combining different‐colored emissions. White organic light‐emitting diodes, therefore, should be fabricated to obtain mixed emissions from different organic luminophores while suppressing energy transfer between each other. Here, the authors present a simple means to realize this goal by forming two‐color strip‐patterns of light‐emitting polymer (orange) and an iridium complex (sky‐blue) luminophores entirely through solution processes. The formation of the two‐color patterns is facilitated by i) the use of a highly efficient crosslinker permitting the construction of structurally robust orange primary strip‐patterns and ii) the contrast in the surface energy allowing selective wetting of the secondary sky‐blue patterns between the orange primary patterns. The emissive layer comprising the two‐color strip ‐patterns allows for the mixing ratio of the two colors to be adjusted by simply varying the areal ratio of the two patterns, which in turn, controls the white emission color‐temperature from 2119 to 7994 K. White organic light‐emitting diodes with two‐color strip‐patterns are fabricated through solution processes. The formation of the two‐color patterns is facilitated using the crosslinkers permitting the construction of orange strip patterns and the contrast in the surface energy allowing selective wetting of the sky‐blue patterns. Warm‐to‐cold white light control is realized by varying the areal ratio of the two‐color strip‐patterns.