sentences: photovoltaic cells are a kind of object
docs: photoelectric_cell is transducer. photovoltaic_electricity_generation is electricity_generation. photoelectricity is electricity. photoelectron is electron. solar_cell is photovoltaic_cell. myeloid_progenitor_cell is tangible_thing. solar_cell is photosensor. photoelectric_cell is detector. solar_cell is electrical_component. photoconductivity is electrical_conduction.