The doping effects and electrical characteristics of rubidium carbonate (Rb2CO3) in organic bipolar charge transport material 2-methyl-9,10-di(2-naphthyl) anthracene (MADN) has been investigated. Utilizing temperature-dependent admittance spectroscopy, the electron injection barrier (so-called activation energy) is verified to be reduced from 1.33 to 0.2878 eV by the incorporation of Rb2CO3 from 0 to 33 vol%. The precision of admittance spectroscopy is further proved by photovoltaic measurement. Higher mobility has achieved using space-charge-limited current (SCLC) determination. Consequently, these enhancements in electron injection and transport yield superior device performance for organic light-emitting diodes (OLEDs).