The Role of Metallic Dopants in Improving the Thermal Stability of the Electron Transport Layer in Organic Light-Emitting Diodes

4,7‐Diphenyl‐1,10‐phenanthroline (BPhen) is widely used to create the electron transport layer (ETL) in organic light‐emitting diodes (OLEDs) because of its high electron mobility and good compatibility with alkali metal n‐dopants. However, the morphology of these ETLs is easily altered by heating due to the relatively low glass transition temperature ( T g ) of BPhen and this change often reduces the performance of OLEDs. Here, an enhancement...