Takahiro Shiga

Design of multiwavelength resonant cavities for white organic light-emitting diodes

We have developed a multiwavelength resonant cavity (MWRC) optical device designed for organic light-emitting diodes (OLEDs). This device consists of two or more wavelength-selective mirrors, where each resonant peak can be adjusted independently, resulting in enhancement of the luminance and modification of the color of emission. We have designed a white OLED with a MWRC by using optical simulation and have confirmed that the white MWRC device is 1.3 times as bright as that of the conventional noncavity one.

EFFECT OF RESIDUAL WATER ON GIANT MAGNETORESISTANCE IN CO/CU SUPERLATTICES

We have studied the effects of residual water during the deposition process and the deposition rate on the giant magnetoresistance (GMR) in Co/Cu superlattices prepared by sputtering. The magnetoresistance (MR) ratio decreases drastically with an increase in the amount of residual water and a decrease in the deposition rate. In order to understand these results, we introduce the residual water to deposition rate ratio parameter, ξ, which is proportional to the exposure of the surface of the sample to residual water. It has been found that the MR and magnetic properties of the superlattices are universally expressed in terms of ξ.

P‐87: Optical Simulation of Organic Light Emitting Diodes

We have developed an optical simulator of OLED performance named “OptDesigner”, which can calculate external emission spectra, color, and luminance of particular structures at every observation angle. Actual OLEDs with different ITO thickness were fabricated for validation. The calculated spectra, color, and luminance at each angle showed a good agreement with the actually observed values.