Details

Autor(en) / Beteiligte

• Parthasarathy, G.
• Shen, C.
• Kahn, A.
• Forrest, S. R.

Titel

Lithium doping of semiconducting organic charge transport materials

Ist Teil von

• Journal of applied physics, 2001-05, Vol.89 (9), p.4986-4992

Erscheinungsjahr

2001

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We study the effects of lithium (Li) incorporation in the cathodes of organic light-emitting devices. A thermally evaporated surface layer of metallic Li is found to diffuse through, and subsequently dope, the electron transporting organic semiconducting thin films immediately below the cathode, forming an Ohmic contact. A diffusion length of ∼700 Å is inferred from analyses of the current–voltage and secondary ion mass spectrometry data. The conductivity of the Li-doped organic films is ∼3×10−5 S/cm. Photoemission spectroscopy suggests that Li lowers the barrier to injection at the organic/cathode interface, introduces gap states in the bulk of the organic semiconductor, and dopes the bulk to facilitate efficient charge transport.