Photofission is a process that happens when light hits certain materials. When light hits those materials, the particles in them (atoms) can break apart into smaller pieces. This is called fission, and when it happens because of light, it is called photofission. Photofission can be used to create energy. This happens because when the atoms break apart they release energy as heat. So, photofission is a process where light breaks apart materials and then creates energy from it.