Efficient fluorescent red, green, and blue organic light-emitting devices with a blue host of spirobifluorene derivative

Abstract

Efficient fluorescent blue, green, and red (RGB) organic light-emitting devices (OLEDs) were fabricated using a blue host material of pyrimidine-containing spirobifluorene derivative 2,7-bis[2-(4- tert-butylphenyl)pyrimidine-5-yl]-9,9′-spirobifluorene (TBPSF) doped with blue dye perylene, green dye 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1 H,5 H,11 H-benzo[l] pyrano[6,7,8-ij] quinolizin-11-one (C545T), and red dye 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4 H-pyran (DCJTB), respectively. The brightness and current efficiency of the perylene doped blue device reached 10117 cd/m 2 and 2.97 cd/A. Green emission of the C545T doped device reached 8500 cd/m 2 and 13.0 cd/A. Red emission of the DCJTB doped device can be as high as 9000 cd/m 2 and 2.0 cd/A, respectively. High color purity of the blue (Commission Internationale de L′Eclairage (CIE x,y ) coordinates (CIE, x = 0.27, y = 0.24)), green (CIE, x = 0.19, y = 0.63) and red (CIE, x = 0.62, y = 0.37) emissions were achieved for RGB dyes doped TBPSF OLEDs. High brightness, large current efficiency, and good color purity of TBPSF-based RGB OLEDs were obtained by the configuration optimization device, such as inserting the hole and electron-injection materials, and suitable dopant content and light emitting layer thickness.