Carrier Transport and Carrier Trap of 8-Hydroxyquinoline Aluminium Thin Films

Abstract

We estimated the trap depth and the trap density of evaporated 8-hydroxyquinoline aluminium (Alq3) thin film using the space charge limited current (SCLC) model and the thermal stimulated current (TSC) method. The current of Alq3 with thickness greater than 200 nm-thickness showed SCLC-like characteristics. The TSC of Alq3 had a peak around -40° C. The trap depth was estimated to be 0.80 eV. The trap density was estimated to be 1.0×1017 cm-3 (SCLC) and 1.4×1015 cm-3 (TSC). The trap influenced the electrical conduction in Alq3 thin film, but it was not the major contributor to EL of Alq3.