Electron transit time and reliable mobility measurements from thick film hydroxyquinoline-based organic light-emitting diode

Electron mobility of Alq₃ was measured by transient electroluminescence experiments using bilayer organic light emitting diodes (OLED). A rectangular voltage pulse was applied to an OLED using a pulse generator. A nitrogen pulsed laser was used to generate photocarriers and a direct current power supply was used to detect the electron photocurrent. Electron mobility extracted from time delay was independent of the thickness of the Alq₃ layer and was in excellent agreement with optical time of flight measurements.