Investigation on Organic Electroluminescent Diode as New Optical Source

Research Project

Project/Area Number	14550339
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	電子デバイス・機器工学
Research Institution	KINKI University
Principal Investigator	OKADA Kazuyuki KINKI Univ., Fac.of Eng., Assistant Prof., 工学部, 助教授 (70177046)
Project Period (FY)	2002 – 2003
Project Status	Completed (Fiscal Year 2003)
Budget Amount *help	¥2,200,000 (Direct Cost: ¥2,200,000) Fiscal Year 2003: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 2002: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywords	Optical Device / Organic Thin Film / Display
Research Abstract	The organic electroluminescent(EL) diode was progressively developed as a display device. In this application, we utilize the lights emitted to the normal direction of the planar EL diode. As the lights are isotropically generated in the organic layer, some of the lights can propagate to the tangential direction and emit from the side end of the device. In this research, the spectrum, angular distribution and polarization of the lights emitted from the side end of the EL diode were experimentally observed and investigated in comparison with those in the normal direction. (1)Spectral features The wavelength at the peak intensity in the emission spectrum from the side end was shorter than that in the normal direction. The spectral width of the lights from the side end was narrower compared with that in the normal direction. These spectral characteristics were obviously observed in the device of the emission area size of 6mm. (2)Angular distribution The lights from the side end of the EL diode with the emission area size of 6mm were observed to be strongly emitted to the direction of 40 degree away from the tangential direction. In the device with narrower emission area, the direction angle of the strong emission was larger than 40 degree. With longer emission wavelengths, this angle was shifted to the smaller one. We expect that these charactristics are related to the light propagation in the EL diode. (3)Polarization characteristics The lights emitted to the normal direction were not polarized, but the lights from the side end were slightly polarized in the normal direction of the EL diode. This polarization characteristics was similar to that in different color EL diode.