Effects of the Na2CO3 dopant on electron injection and transport in organic light emitting devices

► Na2CO3-doped OLEDs have improved opto-electrical properties. ► Na2CO3-doped Alq3 layers possess an enhanced electron injection ability. ► The higher mobility of the Na2CO3-doped samples derived by the SCLC model. ► The reaction between Na2CO3 and Alq3 results in an electron transfer process. ► The Na2CO3-doping moves the Fermi level close to the LUMO of Alq3.