Chiral perovskites for room-temperature spin light-emitting diodes

Light-emitting diodes (LEDs) fabricated based on luminescent materials have revolutionized the full-color display and solid-state lighting technologies [1].Spin LEDs (spin-LEDs) that can emit circularly polarized electroluminescence (CP-EL) show broad promising opto-spintronic applications, including three-dimensional (3D) displays, quantum-based optical computing and information processing, tomography and encryption [2].The efficient control over the spin polarization of the injected charge carriers is the prerequisite for the fabrication of spin-LEDs, which is usually achieved by using polarized ferromagnetic contacts and/or applied magnetic fields.Through the radiative recombination process of spin-polarized charge carriers, spin angular momentum of carriers will then transfer to the light.Finally, circularly polarized light (CPL) with angular momentum is emitted depending on the spin state of the injected charge carriers [2].The degree of polarization of CP-EL of spin-LEDs is defined by P CP-EL using the equation below: