High Stability White Organic Light Emitting Diode with a Single Emitting Layer, SAlq:DCJTB

摘要

Stable organic white light-emitting diodes are fabricated by a single white emitting organic layer, which is Bis (2-methyl-8-quinolinato) (triphenylsiloxy) aluminum (Ⅲ) (SAlq) doped a red fluorescent dye of 4- (dicyanomethylene)- 2-tert-butyl- 6 (1,1,7,7-tetramethyljulolidyl-9-enyl)-4H- pyran (DCJTB). The incomplete energy transfer from blue-emitting SAlq to red-emitting DCJTB enables to obtain a stable balanced white light-emission by the DCJTB doping concentration of 0.5%. A device with the structure of ITO/ TPD(50nm)/ SAlq:DCJTB (30nm, 0.5%)/ Alq_3(20nm)/ LiF(0.5nm)/ Al(110nm) shows a maximum luminance of about 15,000 cd/m~2, an external quantum efficiency (QE) of about 2%, power efficiency of 2.3 Lm/W, and CIE chromaticity coordinates of (0.34, 0.39) at driving current density of 0.3 mA/cm~2 to (0.31, 0.38) at 33 mA/cm~2.