Organic blue light-emitting-diode with phenylbenzeneamine derivative

The authors investigated the electrical and optical properties of the organic light-emitting-diode (OLED) with a phenylbenzeneamine derivative (MDTPA). The PL and EL of MDTPA thin film were blue. However, the EL of the device of indium-tin-oxide(ITO)/MDTPA/aluminum quinoline(Alq3)/meta1 was not due to the emission from MDTPA, but was the emission from Alq3. It can be explained by that the emission region is formed in Alq3 layer since MDTPA has excellent hole transportation. The authors introduced an oxadiazole dimer (OXD) as a carrier blocking layer between MDTPA and Alq3 layers in order to form the emission region in MDTPA layer. This multi-layer OLED was found to have a high performance for a blue-light-emitting EL device. Its luminance was over 3000 cd/m(2) at the current density of 100 mA/cm(2). The EL threshold voltage was about 5 V. Their EL efficiency was about 2 lm/W.