Large magnetoresistance and spin-polarized photocurrent in La2/3Sr1/3MnO3(Co)/quaterthiophene/La2/3Sr1/3MnO3 organic magnetic tunnel junctions

Abstract

Organic magnetic tunnel junctions (OMTJs) have become one of the hot topics in spintronic devices due to their structural adjustability and long spin lifetime. However, the spin-dependent transport properties in OMTJs with different spatial spin-polarized interfaces and their manipulation by light are not yet clear. Here, the spin-dependent transport properties in La_2/3Sr_1/3MnO₃/quaterthiophene/La_2/3Sr_1/3MnO₃ (LSMO/T₄/LSMO) and Co/T₄/LSMO OMTJs with different spatial spin polarizations and their light modulation are investigated systematically by theoretical calculations. It is found that a large tunneling magnetoresistance (TMR) appears in the OMTJs with a large spatial spin-polarized spinterface, wherein TMR will be reduced in the OMTJs with spatial spin polarization inversed spinterfaces. Furthermore, perfect spin injection efficiency can be obtained in both OMTJs. Specifically, the magnetization alignments of the ferromagnetic electrodes in the Co/T₄/LSMO OMTJ can control the switch of the spin channel. Moreover, the fully spin-polarized photocurrent and spin battery appear in parallel and antiparallel magnetization configurations of the LSMO/T₄/LSMO OMTJ, respectively. The results contribute to understanding the spin transport properties and designing multifunctional organic spintronic devices.