Electron injection behavior from the magnesium electrode into a family of electron-transporting amorphous molecular materials, a,ω-bis(dimesitylboryl)oligothiophene

Electron injection behavior from the magnesium (Mg) electrode into a family of electron-transporting amorphous molecular materials, 5,5'-bis(dimesitylboryl)-2,2'-bithiophene (BMB-2T) and 5,5''-bis(dimesitylboryl)-2,2':5',2''-terthiophene (BMB-3T), in single-layer devices of symmetrical structure was studied. The current density-voltage characteristics of the devices with varying thickness were in agreement with the trap-free space-charge-limited current model. The results indicate that the current is conduction limited and that the contact between BMB-nT (n = 2 and 3) and the Mg electrode is nearly ohmic.