Inorganic-organic Hybrid Structured LED's

✍ Scribed by T. Gebauer; G. Schmid

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: German
• Weight: 108 KB
• Volume: 625
• Category: Article
• ISSN: 0372-7874
• DOI: 10.1002/(sici)1521-3749(199907)625:7<1124::aid-zaac1124>3.0.co;2-t

✦ Synopsis

Three-layered heterocontact light emitting diodes (LED's) were generated by spin-coating processes. Perovskites of the type [C 6 H 5 (CH 3 )CHNH 3 ] 2 PbX 4 (X = Cl, Br) on ITO glass served as p-semiconductors, while 1,3,5-[5-(4-tertbutylphenyl)-2-oxadiazyl]benzene (Starburst) in polystyrene was selected as the organic n-semiconductor. As a zone for the electron-hole recombination between p-and n-semiconductor layer a poly(N-vinylcarbazole)-layer, doped with 3-(2-benzothiazolyl)-7-diethylamino-coumarin (Coumarin6), as emitter molecule was used. A Mg : Ag electrode served as the cathode on the Starburst : polystyrene blend. Both diodes showed green luminescence at 7 V. The external quantum yield of the diode with the PbCl 4 2± perovskite was 0.4%, but only 0.06% for PbBr 4 2± . This is due to the different band structures of the layered perovskites.