Alq3: ab initio calculations of its structural and electronic properties in neutral and charged states

A detailed density functional theory study is presented for the structural and electronic properties of Alq3, one of the electroluminescent material most successfully used in organic light-emitting diodes. Both geometrical isomers are considered, and interesting discrepancies are found in their electronic behavior. Calculations are compared with available experimental data and with the results of semiempirical models as well. The effects of hole and electron injection are clarified, and trap energies for the negative charge carriers are estimated.