Novel solar absorptive and infrared reflective properties of Cu-doped Sm_0.5Sr_0.5CoO_3−δ

Cu²⁺ doped Sm_0.5Sr_0.5CoO_3−δ perovskite oxides were synthesized via the conventional solid state reaction method. The effect of Cu doping concentration on composition, electrical conductivity, solar absorbance and infrared emittance of Sm_0.5Sr_0.5Co_1−xCu_xO_3−δ were investigated. It was found that the structure of the samples was orthorhombic perovskite phase. The second phase SrCoO_2.8 was detected in the samples with Cu doped concentration for x = 0.2–0.5. The electrical conductivity decreased due to the substitution of Co³⁺ ion by Cu²⁺ ion decreasing the overlapping of Co 3d orbital and O 2p orbital and influencing the effective electron transfer from Co³⁺ ion to Co⁴⁺ ion. In addition, the optical properties of the samples were discussed, and the results showed the thermal emittance increased gradually from 0.29 to 0.74 and the solar absorbance changed slightly from 0.70 to 0.88 with increased Cu²⁺ doping. These results indicate the oxides Sm_0.5Sr_0.5Co_1−xCu_xO_3−δ have a good application prospect in the field of solar energy.