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Laser‐driven projection display puts forward urgent demand for color converter materials to achieve wide‐color‐gamut and high‐quality image presentation. In this study, a hierarchical structure quantum dots‐in‐glass film (QiGF) is fabricated via co‐sintering stable green/red‐emitting CsPbX3@glass (X3 = Br3, Br1.5I1.5) and commercial low‐melting glass on the sapphire substrate. Benefiting from the well‐retained optical properties of CsPbX3 quantum dots in amorphous glass and high thermal conductivity, QiGF succeeded in inhibiting luminescence saturation after 20 W mm−2 blue laser irradiation. A brand‐new white‐lighting source designed by coupling a blue laser with a pattern "QiGF wheel" produced ultra‐narrow blue/green/red tri‐color emissions and total luminous flux of 146 lm. Accordingly, a QiGF‐converted laser projection system is successfully designed for the first time, showing more natural and real color restoration for its wide color gamut display feature (157% of conventional light‐emitting diode projection and 107% of NTSC standard). The present study highlights the practical application of CsPbX3 quantum dots composite as an efficient laser‐driven color converter in projection display. [ABSTRACT FROM AUTHOR]

Exploiting the spin degree of freedom to store and manipulate information provides a paradigm for future microelectronics. The development of van der Waals (vdW) heterostructures has created a fascinating platform for exploring spintronic properties in the two-dimensional (2D) limit. Transition-metal dichalcogenides such as tungsten diselenide (WSe2) have electronic band structures that are ideal for hosting many exotic spin–orbit phenomena. Here, we report the spin-filtering effect in all-vdW heterostructures with WSe2 barrier. Combining 2D-perpendicular magnetic anisotropy Fe3GeTe2 (FGT) with different thicknesses of WSe2, the FGT/WSe2/FGT spin valve shows distinct charge and spin transport behavior. Moreover, the negative magnetoresistance (−4.3%) could be inverted into positive magnetoresistance (up to +25.8%) with decreasing the WSe2 thickness. Furthermore, we proposed a spin-filtering model based on Δ-symmetry electrons tunneling to explain the crossover from negative to positive MR signal through ab initio calculation. These experimental and theoretical results illustrate the rich potential of the families of TMDC materials to control spin currents in 2D spintronic devices. [ABSTRACT FROM AUTHOR]

Spintronics research has been of emerging interest in the inorganic and organic electronics field, and magnetic materials play an important role in spintronics. Here, the spin valve (SV) devices are reported based on few‐layered van der Waals semiconducting WSe2 or InSe sandwiched between room‐temperature ferromagnet Pt/Co/Ru and exfoliated layered ferromagnetic metal Fe3GeTe2 (FGT). The metallic interface rather than the Schottky barrier is formed despite the semiconducting nature of WSe2 and InSe, which may be originated from the interface hybridization with Pt/Co/Ru and FGT. The magnetoresistance of both devices persists up to the Curie temperature of FGT, and the magnitude of the magnetoresistance does not vary with the applied current, which indicates these devices have stable device performance. The work reveals that easily fabricated Pt/Co/Ru multilayers could be stable 3D perpendicular magnetocrystalline anisotropy (PMA) spin injection electrodes applied in SV devices, facilitated by combining 2D magnets, which is expected to be an attractive candidate for 2D applications. [ABSTRACT FROM AUTHOR]

Currently, advanced optical security techniques are imminent in response to the increasingly rampant counterfeit and pirated goods on a global scale. Herein, hexagonal Na(NdxY1−x)F4 (x = 0–1) solid‐solution nanocrystals (NCs) embedded glasses are successfully fabricated via in situ glass crystallization. Benefited from the protection of inorganic glass, Na(NdxY1−x)F4 NCs exhibit superior long‐term stability and can endure high‐power 808 nm laser irradiation. Importantly, opposite variations between near‐infrared (NIR) luminescence and laser‐induced temperature can be detected for the nanocomposites, which are sensitive to Nd3+ doping concentration. As a proof‐of‐concept experiment, Nd3+ concentration dependent anti‐counterfeiting patterns with high‐concealment and high‐precision are designed and show bright emission and dimmish thermal images in Nd3+‐tenuous composites under the irradiation of 808 nm laser, while opposite displays can be achieved in Nd3+‐enriched one. This kind of information encryption triggered by a commercial single light source to achieve dual opposing displays in one material can effectively improve security in anti‐counterfeiting. [ABSTRACT FROM AUTHOR]

Perovskite quantum dots are considered to be one of the most promising materials for next-generation backlight displays due to their narrow emission width, high color purity and tunable luminescence. However, the deterioration and failure of perovskite quantum dots under stimulation from the external environment (e.g., light, heat, and humid air) limit their practical applications. Herein, CsPbBr3@glass with excellent stability and optical properties was successfully prepared by optimizing the quantum dot nucleation/growth conditions. The CsPbBr3@glass@PDMS hierarchical structure film with a full width at half maximum of ∼17 nm and photoluminescence quantum yield of ∼80% was obtained via the physical dilution method to eliminate the internal filtering effect. Benefiting from the dual protection of the inorganic glass network and PDMS polymer matrix, the film exhibited excellent water/heat resistance. As an application demonstration, a white LED backlit unit was designed by coupling a CsPbBr3@glass@PDMS green film and Mn4+:K2SiF6 red film with a home-made blue light guide panel, endowing the LCD with a wide color gamut (a color gamut of 159% for commercial LCD, 108% for NTSC, and 81% for Rec. 2020), confirming its great potential in the display industry. [ABSTRACT FROM AUTHOR]