Showing papers by "Jin Young Oh published in 2010"

Energy Barrier Reduction and Exciton Confinement Using an Intermediate Blocking Layer in Organic Light-Emitting Diodes

Abstract: The intermediate blocking layer (IBL) was investigated for the development of highly efficient and bright organic light-emitting diodes (OLEDs). The insertion of an IBL between a hole transport layer and an emitting layer (EML) has resulted in the development of highly efficient and bright OLEDs. The quantum efficiency and electrical durability at high voltage were highly dependent on the thickness of the IBL. The maximum external quantum efficiency of the devices with a 1.5-nm-thick IBL was increased by 28% compared with the reference. The enhanced performance of the OLEDs appears to be due to the improvement of carrier balance and exciton confinement.

Observation of the hollow cathode effect from a dielectric cathode

Abstract: The hollow cathode effect (HCE) is investigated in the dielectric hollow cathode structure in a Ne?Xe mixture at 4%. The influence of the dielectric is shown experimentally by the relationship between voltage and current peaks. The linearity of reduced current density confirms the existence of the HCE and shows that cathode fall has the same value at every pD condition. Varying the pD, the variation in the discharge mode can be measured with IR intensity emitted from the plasma and photographs of discharge in the visible part of the spectra. Voltages and current in the range of 3?kV at 10??A were used. We suggest an electrode configuration reinforced in cathode sputtering for the display panel and light source using the dielectric hollow cathode discharge (DHCD), and introducing a mechanism of the DHCD mode.