Does dynamic Rashba splitting slow radiative recombination in perovskites
In plain words
Heavy lead atoms and a fluctuating lattice could split the energy bands by spin, making light emission slightly indirect and slower. Whether this effect is large enough to matter is disputed.
Precise statement
Inversion-breaking lattice fluctuations in MAPbI3 could produce a dynamic Rashba splitting that offsets the band extrema in momentum and lowers the bimolecular radiative coefficient $B$ (measured of order $1e-10\,\mathrm{cm}^3/\mathrm{s}$). Determine the size of the room-temperature splitting (static or dynamic, in meV) and its effect on $B$, with photon recycling separated out. An answer is the splitting value and the fractional change of $B$.
What would settle it
Spin- and momentum-resolved photoemission or circularly polarized spectroscopy at room temperature combined with molecular-dynamics band-structure calculations.