A study of light-emitting diodes constructed with copolymers having cyclohexyl thiophene and hexyl thiophene units

✍ Scribed by Vibha Saxena; V. S. Shirodkar

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 146 KB
• Volume: 77
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/1097-4628(20000801)77:5<1051::aid-app12>3.0.co;2-a

✦ Synopsis

We report visible light emission from a diode made from copolymers of 3-alkylthiophenes. These chemically synthesized copolymers exhibit improved electroluminescence and quantum efficiencies compared to poly (3-cyclohexylthiophene). Good solubility of copolymers allows the fabrication of the light emitting diodes by spin-cast polymer film. The devices emit greenish-blue light in wavelength region of 550 -580 nm, which is easily visible in poorly lighted room. The quantum efficiencies are in the range of 0.002 to 0.01% (photons per electron) at room temperature; which are significantly higher than corresponding values for poly(3-cyclohexylthiophene) based light emitting diodes. The charge carrier mobility in the device is found to be 5.6 ϫ 10 Ϫ4 cm 2 / Vs.