Ultracold neutrons (UCN) have been produced using the cold neutron (CN) beam FUNSPIN at SINQ on cryogenic oxygen (O₂), tetradeuteromethane (C²H₄), and deuterium (²H₂) targets. The target cell (40 mm long, fiducial volume about 45 cm³) was operated between room temperature and 8 K and UCN were produced from gaseous, liquid and solid targets. UCN rates have been measured as a convolution of UCN production and transport out of the target and to the detector. At least within the accessible temperature range of this experiment, deuterium outperforms the other materials
