Patent ID: 8895353

Claim:
A method of increasing the performance of a multilayer polymer light emitting diode that contains an emissive layer, a cationic conjugated polyelectrolyte electron injection layer, and a cathode, the method comprising: selecting and including a counter anion having oxidative properties in the electron injection layer; pulse biasing and non-pulse biasing the polymer light emitting diode, wherein: the pulse biasing suppresses ion accumulation at an emissive layer/electron injection layer interface and at an electron injection layer/cathode interface, and the non-pulse biasing allows ion accumulation at the emissive layer/electron injection layer interface and at the electron injection layer/cathode interface; and measuring and comparing luminous efficiency of the pulse biased and non-pulse biased polymer light emitting diode to establish whether pulse biasing the polymer light emitting diode increases the luminous efficiency as compared to non-pulse biasing the polymer light emitting diode.