Electron Injection into an Alq3 Single-Layer Organic Light-Emitting Diode

Electric field and temperature-dependent electron injection studies have been performed in an aluminum (Al)/tris(8-hydroxy-quinolinolato)aluminum (Alq3)/magnesium (Mg):silver (Ag) single-layer organic light-emitting diode (OLED). Semiconductor text book theories, such as Fowler-Nordheim (FN) model for tunneling injection or Richardson-Schottky (RS) model for thermionic emission cannot account for the experimentally observed dependence of the injection current on electric field and temperature. Excellent agreement with experiment is provided by a Monte Carlo simulation of carrier injection from a metal into an organic dielectric with random hopping sites.