Hot OLEDs can "switch back"

Due to their fascinating properties, organic light-emitting diodes (OLEDs) are increasingly used in devices such as smartphone displays or television screens. Large-area OLEDs are also becoming increasingly interesting for new lighting concepts. For the design of such components, the non-linear effect of the self-heating of the materials as well as a resulting switch-back effect must be considered appropriately. Researchers from the TU Dresden and the Weierstrass Institute recently published a paper on Experimental proof of Joule heating-induced switched-back regions in OLEDs in the renowned scientific journal nature research - Light: Science & Applications (2-year impact factor: 14.000, 5-year impact factor: 15.132).

Figure: Luminance in a large-area OLED. Due to the interplay of current flow and self-heating, regions with negative differential resistance and "switched back" behavior are forming in the OLED (luminance decreases despite increasing supplied currents)..