Tuning Emission Colors from Blue to Green in Polymeric Light-Emitting Diodes Fabricated using Polyfluorene Blends

Author(s)

Quites, Jr., Fernando ^[1] ; Faria, Gregorio Couto ^[2] ; Germino, Jose Carlos ^[1] ; Zambon Atvars, Teresa Dib ^[1]

Affiliation

^[1] Univ Estadual Campinas, Inst Chem, BR-13084971 Campinas, SP - Brazil

^[2] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Journal of Physical Chemistry A; v. 118, n. 45, p. 10380-10390, NOV 13 2014.
• Web of Science Citations: 12

Abstract

The photo- and electroluminescent properties of single-layer two-component blends composed of one blue emitter polymer and one green emitter polymer were studied. The blue emitter, poly{[}(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(9,9-di-[5'-pentanyl]-fl uorenyl-2,7-diyl)] (PFOFPen), was used as the matrix, and the green emitter, poly{[}(9,9-dihexylfluorenyl-2,7-diyl)-alt-co-(bithiophene)] (F6T2), was used as the guest. The F6T2 content in the blends varied from 0.0075 wt % to 2.4 wt %. Remarkable differences were observed between the electroluminescent (EL) and photoluminescent (PL) spectra of these blends, which indicated that the mechanism for excited-state generation in the former process had a higher efficiency in the aggregated phase than in the nonaggregated phase. Blending these two polymers gradually tuned the emission color from blue (PFOFPen and blends with <0.75 wt % F6T2) to green (F6T2 and blends with >0.75 wt % F6T2). The photophysical processes involved in both EL and PL emission are also discussed. (AU)

• FAPESP's process: 13/16245-2 - Photophysical properties of thin films of conjugated polymers
• Grantee: Teresa Dib Zambon Atvars
• Support Opportunities: Regular Research Grants