Could this be used to create a nuclear power generator without moving parts? Some radioactive material in the center, some coating to absorb the radiation, and a shell of these cells to generate electricity.
One of the proposed ideas for nuclear rocket propulsion would contain a fissioning gas cloud inside a fused-silica glass blub. At a temperature of several thousand degrees (5,000 - 20,000 K), incandescent light escapes the glass, and gets absorbed by the hydrogen propellant (with bits of solid dust flowing through it as an opacifier). That's one-half of your idea: there's no photovoltaic component, but it does examine the "nuclear fission reactor as an optical light source" half.
https://en.wikipedia.org/wiki/Nuclear_lightbulb
https://sci-hub.se/10.2514/6.1991-3512 (pdf) ("Summary of nuclear light bulb development status" (1991))
excerpt:
- "The gas core Nuclear Light Bulb (NLB) propulsion system could provide both the desired thrust and specific impulse. Initial gas core nuclear rocket (GCNR) investigations started in the 1950s when two somewhat different concepts emerged; an open-cycle GCNR and a closed-cycle GCNR (named the Nuclear Light Bulb). The open cycle configuration (Fig. 1) isolates hot fissioning gas from the chamber walls by flowing cooler propellant around the hot gas. Although some nuclear fuel will diffuse into the propellant and exhaust into space, the theoretical amount was considered too small to be of consequence. NASA-Lewis pursued the open cycle by both analysis and laboratory experiments from the ’50s through the early ‘70s.’"
- "At the same time, United Technologies Research Center, then United Aircraft Research Laboratory, explored the closed cycle NLB concept (Fig. 2).[2,3] Hot fissioning fuel in a gaseous state is confined within a transparent wall of fused silica by a vortex of tangentially injected buffer gas that is also transparent to thermal radiation. Hydrogen propellant, seeded with micron-size tungsten particles to absorb the thermal radiation from the hot fuel, flows axially outside the fused silica wall and is exhausted through thrust nozzles. Complete fuel containment requires continuous withdrawal of a small fraction of the mixture of fuel and buffer gas for reprocessing and reinjection into the vortex flow."