Discrimination and control of the exciton-recombination region of thermal-stressed blue organic light-emitting diodes.

Organic light-emitting diodes (OLEDs) suffer from carrier imbalance under high temperatures. We improved their thermal stability by using space interlayers adjacent to the charge transport layers. The current efficiency of the optimized OLEDs increased under high temperature, with an increase of over one order of magnitude of the electron mobility.