Improved OLED devices and methods of making the same using vertical phase separation to simplify processing. Vertically phase separated material can include at least one lower first layer disposed on the electrode, and at least one upper second layer different from the first layer and disposed away from the electrode or optionally on one layer comprising at least one semiconducting organic material. The first layer can be enriched with at least one first semiconducting organic material (SOM 1) and the second layer can be enriched with at least one second semiconducting organic material (SOM 2) different from the SOM 1. The ink composition can be adapted so that the film vertically phase separates into the first and second layers. Compositions and devices are also embodied herein.