  Organic light-emitting diodes (OLEDs) are the leading self-emitting pixel
technology in current and future small and large area displays. Once integrated
with a certain layer architecture into the backplane layout, their emission
colour and angular distribution is set by the optical properties of the layered
system. In this paper, we demonstrate a pixel design that allows for actively
controlled variation of the angular emission profile of the individual vertical
pixel. For this, a tandem device is developed that comprises two units
optimized for different angular emission pattern. We constrained the system to
operate in a narrow emission band to maintain monochromaticity of the
individual pixel. We discuss this concept for a red phosphorescence-based OLED
stack and give an outlook based on simulations for the other primary display
colours green and blue. The tandem unit can be operated with only two
electrodes making use of the AC/DC driving concept, where the outer electrodes
are in direct connection. In this paper, we will discuss the potential, status,
and technology challenges for this concept.
