In any (deep) spacecraft, radiation shielding is paramount. Neutrons and gamma rays can only be stopped by putting mass (or distance) between source and target. It seems that one should put more lightweight elements on the outside of the hull for proper shielding.
I wonder if PV cells could provide this kind of neutron absorption/deflection layer and if so at what cost. My rationale is to generate a secondary usage to the inevitable mass. For a larger spacecraft it might e.g. be viable to partially rely on solar instead of nuclear power in order to reduce radiation exposure to the crew.
How does a typical solar cell compare as a neutron shield?