This paper focuses on the defect-dependent carrier and spin transport across P- \(\hbox {Si/NiFe}_2\hbox {O}_4\) \(\hbox {(NFO)/Alq}_3\) /Al ferromagnet/organic semiconductor interfaces. The \(\hbox {NFO/Alq}_3\) and \(\hbox {Al/Alq}_3\) defect states are considered principally responsible for carrier transport at positive and negative biases, respectively. At maximum positive voltage, carriers created by \(\hbox {NFO/Alq}_3\) interfaces become trapped at empty \(\hbox {Al/Alq}_3\) defects. This creates a space charge region at \(\hbox {Al/Alq}_3\) interfaces, thereby restricting further carrier injection from electrodes. Change in magnetic field sweep direction from 0 \(\rightarrow\) H to H \(\rightarrow\) 0 resulted in significant fall in maximum positive magnetoresistance (MR) response from \(\sim\) 160% to \(\sim\) 40%, respectively. The values have been recorded at 3.16V applied voltage and 380 Oe applied magnetic field. The results indicate reduction of spin flip scattering process with magnetic field at \(\hbox {NFO/Alq}_3\) interface of the device. Such property of spin relaxation process modification with field sweep direction may help these devices to be employed for spintronic memory applications.
