Improved Polarization in the Sr6Cd2Sb6O7Se10 Oxyselenide through Design of Lateral Sublattices for Efficient Photoelectric Conversion

Highly-polarizable materials are favorable for photoelectric conversion due to their efficient charge separation, while precise design of them is still a big challenge. Herein a novel polar oxyselenide, Sr6 Cd2 Sb6 O7 Se10 , is rationally designed. It contains lateral sublattices of polarizable [Sb2 OSe4 ]4- chains and highly-orientated [CdSe3 ]4- chains. The intense polarization was evaluated by significant second-harmonic generation (SHG) signal (maximum: 12.6×AgGaS2 ) in broad spectrum range. The polarization was found to mainly improve the carrier separation with a much longer recombination lifetime (76.5 μs) than that of the nonpolar compound Sr2 Sb2 O2 Se3 (18.0 μs), resulting in better photoelectric performance. The single-crystal photoelectric device exhibited excellent response covering broad spectrum in 500-1000 nm with stable reproducibility. This work provides some new insights into the structure design of highly-polarizable heteroanionic materials for photoelectric conversion.