Extremely-high-density carrier injection and transport over 12000 A/cm2 into organic thin films -: art. no. 083502

We achieved extremely-high-density steady state carrier injection and transport at over similar to 10000 A/cm(2) into organic thin films using high thermally conductive substrates, which suppress the temperature rise inside the devices by transferring the joule heat into the substrates. Using a silicon substrate with a high thermal conductivity of 148 W/mK and a small size cathode with a radius of r = 25 mu m, we achieved a maximum current density of J(max) = 12222A/cm(2) and power density of P-max similar to 10(5) W/cm(2) in an ITO(110 nm)/copper phthalocyanine (CuPc) (25 nm)/MgAg(100 nm)/Ag(10 nm) device during a fraction of a second under direct current sweep. Further, we also achieved J(max) = 514 A/cm(2) in a conventional organic light-emitting diode structure using the same techniques. In the CuPc based devices, we observed characteristic current density (J)-voltage (V) behavior, indicating that the J-V characteristics are controlled by the trap-free space-charge-limited cur-rents in the high current region, and by the trapped-charge-limited current in the low current region. (c) 2005 American Institute of Physics.