White organic light emitting diodes based on fluorene-carbazole dendrimers

In this paper, we report on theProd. Type: FTP fabrication and characterization of blue and white light emitting devices based on two fluorene-carbazole containing dendrimers and para-sexiphenyl (6P) oligomers. Blue light emitting diodes were fabricated using 9′,9″-(9,9-dioctyl-9H-fluorene-2,7-diyl)bis-9′H-9,3′:6′,9″-tercarbazole (OFC-G2) and 9′,9″-(9,9′-spirobi[fluorene]-2,7-diyl)bis-9′H-9,3′:6′,9″-tercarbazole (SBFC-G2) dendrimers as a hole transport and emissive layer (EML) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) as an electron transport layer. White light emitting diodes were fabricated using 6P and these two dendrimers as an EML. OLED device with the structure of ITO/PEDOT:PSS (50nm)/OFC-G2 (40nm)/6P (20nm)/LiF:Al (0.5:100nm) shows maximum luminance of nearly 1400cd/m2 and a Commission Internationale de l'Eclairage chromaticity coordinates of (0.27, 0.30) at 12V. •White organic light emitting diodes have been fabricated using two fluorene-carbazole dendrimers and para-sexiphenyl (6P) oligomers.•When only these two dendrimers are used as EML, OLED devices are emitted blue light.•The emission colors of OLED devices change from blue to white when 6P is coated on dendrimer films.