Molecular Control of Electron and Hole Injection at Electrodes and at Organic Layer Interfaces in Organic Electroluminescent Devices

In order to improve power efficiency of standard multilayered organic electroluminescent (EL) devices, i.e., ITO/HTL/ETL/M or ITO/HTL/EML/ETL/ M, enhanced electron and enhanced hole injection at an ETL/M and an ITO/ HTL interface, respectively, have been investigated as have those at an HTL/ ETL, an HTL7EML, and an EML/ETL interface by designing proper charge injection at these interfaces. Here ITO, HTL, ETL, EML, and M are abbreviations for an indium-tin-oxide anode, a hole transport layer, an electron transport layer, an emissive layer, and a metal cathode, respectively.