Likely I don't know enough about the components involved, but I've wondered for years about the viability of a solar cell as the bottom layer for AMOLED screens

Likely I don't know enough about the components involved, but I've wondered for years about the viability of a solar cell as the bottom layer for AMOLED screens since those don't need a white/reflective back layer for lighting behind an LCD panel. Even if the diode electronics blocked a big chunk of the light I suspect there are plenty of places where a low usage always charged phone might be desirable.