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

Multicolor Fluorescent Inks Based on Lanthanide Hybrid Organogels for Anticounterfeiting and Logic Circuit Design

With the rapid development of information technology, the encrypted storage of information is becoming increasingly important for human life. The luminescent materials with a color-changed response under physical or chemical stimuli are crucial for information coding and anticounterfeiting. However, traditional fluorescent materials usually face problems such as a lack of tunable fluorescence, insufficient surface-adaptive adhesion, and strict synthesis conditions, hindering their practical applications. Herein, a series of luminescent lanthanide hybrid organogels (Ln-MOGs) were rapidly synthesized using a simple method at room temperature through the coordination between lanthanide ions and 2,6-pyridinedicarboxylic acid and 5-aminoisophthalic acid. And the multicolor fluorescent inks were also prepared based on the Ln-MOG and hyaluronic acid, with the advantages of being easy to write, color-adjustable, and water-responsive discoloration, which has been applied to paper-based anticounterfeiting technology. Inspired by the responsiveness of the fluorescent inks to water, we designed a logic system that can realize single-input logic operations (NOT and PASS1) and double-input logic operations (NAND, AND, OR, NOR, XOR). The encryption of a binary code can be actualized utilizing different luminescent response modes based on the logic circuit system. By adjusting the energy sensitization and luminescence mechanism of lanthanide ions in the gel structure, the information reading and writing ability of the fluorescent inks were verified, which has great potential in the field of multicolor pattern anticounterfeiting and information encryption