Nanomaterials

MgAl layered double hydroxides (LDHs) films were prepared via an in-situ growth method on anodized AZ31 magnesium alloy. Subsequently, phytic acid (PA) was loaded as a corrosion inhibitor through an anion-exchange process. The structural evolution of the LDHs nanosheets during the loading process was systematically investigated. The structure, morphology, and composition of the films were characterized using field-emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and glow discharge optical emission spectroscopy. The corrosion behavior was evaluated using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results revealed that during the first four hours of ion exchange in the PA solution, the LDHs nanosheets underwent a fragmentation–recrystallization process. The incorporation of the corrosion inhibitor significantly enhanced both the stability of the LDHs nanosheets and the long-term corrosion protection of the substrate. Furthermore, a recrystallization mechanism for the LDHs nanosheets on the anodized AZ31 Mg alloy is proposed.

InAs quantum-dot-containing GaAs-based photoconductive antenna (PCA) devices are promising for terahertz (THz) generation under below-bandgap excitation by ultrafast laser pulses. This paper describes the results of rate equation analyses of these devices by assuming the two-step photocarrier generation via midgap states in GaAs and carrier capture into the quantum dots. In the present simulation model, the Coulomb space charge screening effect and the radiated THz field screening effect are taken into consideration. The calculations indicate that, at low excitation powers, the radiated THz field is primarily governed by the fast photocurrent transient arising from rapid electron capture into the quantum dots. At higher photoexcitation power, the THz radiation is controlled predominantly by the carrier velocity reduction immediately after the excitation pulse due to the Coulomb space charge screening effect. As the photoexcitation power increases, the Coulomb screening effect causes saturation of the THz field amplitude, whereas the radiated THz field screening effect contributes little to the saturation of the THz field amplitude. In this study, the influence of key parameters, such as the density and electron capture time of the midgap states and quantum dots, are analyzed. Existing experimental data on THz emission characteristics are discussed on the basis of the present analysis. The observed features provide comprehensive understanding on the THz generation process involving many physical parameters in PCAs and can be applied to optimizing design for high-performance devices.

CsPbBr₃ quantum dots (QDs) have been widely applied in lighting, detection, display, and many other fields. However, due to their ionic crystal nature, further improvement in stability is still required for practical applications. To address this issue, this study employed a ligand engineering strategy to synthesize tributylphosphine (TBP)-modified CsPbBr₃ QDs in a Zn²⁺-containing reaction system. Experimental results demonstrate that the modified QDs exhibit superior optical properties, as well as significantly enhanced thermal stability and resistance to UV photodegradation. The introduction of Zn²⁺ into the reaction system leads to a more uniform size distribution, improved monodispersity, and enhanced crystallinity of CsPbBr₃ QDs. More importantly, the photostability of CsPbBr₃ QDs under varied temperatures, cyclic heating–cooling processes, and prolonged UV irradiation is notably improved after Zn²⁺ incorporation. Furthermore, the TBP-modified CsPbBr₃ QDs synthesized with Zn²⁺ assistance exhibit further enhanced photostability under all the aforementioned aging conditions. Additionally, we introduce a data-sonification method that translates the temporal evolution of photoluminescence spectra into audible audio signals using an oboe timbre, enabling auditory visualization of the aging process. This work not only provides an effective strategy for stabilizing perovskite QDs but also opens new possibilities for the application of luminescent materials in interactive displays.