  Spin accumulation in semiconductor structures at room temperature and without
magnetic fields is key to enable a broader range of opto-electronic
functionality. Current efforts are limited due to inherent inefficiencies
associated with spin injection into semiconductor structures. Here, we
demonstrate spin injection across chiral halide perovskite/III-V interfaces
achieving spin accumulation in a standard semiconductor III-V
(AlxGa1-x)0.5In0.5P multiple quantum well (MQW) light emitting diode (LED). The
spin accumulation in the MQW is detected via emission of circularly polarized
light with a degree of polarization of up to ~15%. The chiral perovskite/III-V
interface was characterized with X-ray photoemission spectroscopy (XPS), cross
sectional scanning Kelvin probe force microscopy, and cross section
transmission electron microscopy (TEM) imaging, showing a clean
semiconductor/semiconductor interface where the fermi-level can equilibrate.
These findings demonstrate chiral perovskite semiconductors can transform
well-developed semiconductor platforms to ones that can also control spin.
