New architectures for high performance polymer light-emitting diodes introducing a solution-processed titanium oxide layer

By introducing a solution-based titanium oxide (TiOx) layer between the polymer and Al electrode in polymer lightemitting diodes, we have demonstrated that the devices exhibit an enhanced efficiency. The TiOx layer reduces the barrier height between the polymer and Al cathode, thereby facilitating the electron injection in the devices and enhancing the device performance by achieving a balance of charge injection and transport between the electrons and holes. Moreover, we also believe that the TiOx layers prevent the diffusion of metal ions into the emitting polymers during the Al deposition process, and reduce the degree of quenching centers in the active polymers.