White organic light emitting devices(OLEDs) with the structure of ITO/m-MTDATA:x%4F-TCNQ/NPB/TBADN:EBDP:DCJTB/Bphen:Liq/LiF/Al are demonstrated.A p-doping transport layer that includes 4F-TCNQ doped into m-MTDATA is used as hole transporting layer(HTL) and an n-doping transport layer comprised of Liq doped into Bphen is used as electron transporting layer(ETL) to lower cathode barrier and facilitate carrier injection.An effective carrier balance(the number of holes is equal to the number of electrons) betwe...