Enhancing circular polarization of photoluminescence of two-dimensional Ruddlesden–Popper perovskites by constructing van der Waals heterostructures

Two-dimensions Ruddlesden–Popper perovskites (RPPs) are promising materials for spintronic devices due to the spin–orbit coupling. However, a relative low spin related photoluminescence (PL) circular polarization is observed from RPPs at room temperature due to the spin relaxation and spin flip caused by the soft lattice of RPPs. Here, we report the enhancement of the circular polarization of PL of RPPs by reducing the carrier lifetime of RPPs via constructing van der Waals heterostructures. We observed the maximum PL polarization of RPPs reaching about 30%. Moreover, we found that the degree of the polarization decreases as the thickness of the heterostructure becomes thicker. Our work provides an effective method to enhance the spin polarization of RPPs and could promote the RPPs based spintronics.