The electron mobilities of 4,7-diphenyl-1,10-phenanthroline (BPhen) doped 8-hydroxyquinolinatolithium(Liq) at various thicknesses (50-300nm) have been estimated by using space-charge-limited current measurements.It is observed that the electron mobility of 33 wt% Liq doped BPhen approaches its true value when the thickness is more than 200nm.The electron mobility of 33 wt% Liq doped BPhen at 300 nm is found to be～5.2×10-3 cm2/(V·s)(at 0.3 MV/cm) with weak dependence on electric field,which is about one order of magnitude higher than that of pristine BPhen(3.4×10-4 cm2/(V·s)) measured by SCLC.For the typical thickness of organic light-emitting devices,the electron mobility of doped BPhen is also investigated.
