Doping Zn²⁺ in CuS Nanoflowers into Chemically Homogeneous Zn_0.49Cu_0.50S_1.01 Superlattice Crystal Structure as High-Efficiency <i>n</i>‑Type Photoelectric Semiconductors

Doping Zn²⁺ in CuS nanoflower into chemically homogeneous superlattice crystal structure is proposed to convert <i>p</i>-type CuS semiconductor to an <i>n</i>-type CuS semiconductor for significantly enhanced photoelectric response performance. In this study, the chemically homogeneous Zn-doped CuS nanoflowers (Zn_0.06Cu_0.94S, Zn_0.26Cu_0.73S_1.01, Zn_0.36Cu_0.62S_1.02, Zn_0.49Cu_0.50S_1.01, Zn_0.58Cu_0.40S_1.02) are synthesized by reacting appropriate amounts of CuCl and Zn­(Ac)₂·2H₂O with sulfur powders in ethanol solvothermal process. By tuning the Zn/Cu atomic ratios to ∼1:1, the chemically homogeneous Zn-doped CuS nanoflowers could be converted to the perfect Zn_0.49Cu_0.50S_1.01 superlattice structure, corresponding to the periodic Cu–S–Zn atom arrangements in the entire crystal lattice, which can induce an effective built-in electric field with <i>n</i>-type semiconductor characteristics to significantly improve the photoelectric response performance, such as the lifetime of photogenerated charge carriers up to 6 × 10^–8–6 × 10^–4 s with the transient photovoltage (TPV) response intensity to ∼44 mV. This study reveals that the Zn²⁺ doping in CuS nanoflowers is a key factor in determining the superlattice structure, semiconductor type, and the dynamic behaviors of charge carriers