It has recently been reported that spinel-type sulfide (Zn,Mg)Sc2S4 possesses superior optoelec-tronic properties, including both n- and p-type dopability and strong visible-light emission. Herein, we present a novel isomorphic selenide, ZnSc2Se4, synthesized using a high-pressure synthesis technique, which exhibits n-type semiconducting behavior. Additionally, a complete solid solution between ZnSc2S4 and ZnSc2Se4 is realized, enabling continuous tuning of direct optical band gaps from 2.07 to 1.35 eV (visible to near-infrared) by adjusting the S/Se ratio, accompanied by a sharp electrical conduc-tivity enhancement. These results revealed that the spinel-type chalcogenide system is a highly promising platform for photovoltaic absorbers. Furthermore, by substituting isovalent Mg [(Zn1āzMgz)Sc2(S1āxSex)4], the band gap would be precisely controlled across nearly the entire visible region (2.86ā1.35 eV), provid-ing additional tunability for high-efficiency light-absorbing and emitting applications in the same host lattice.
