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Environmentally Robust Memristor Enabled by Lead‐Free Double Perovskite for High‐Performance Information Storage
摘要： Memristors are emerging as a rising star of new computing and information storage techniques. However, the practical applications are severely challenged by their instability toward harsh conditions, including high moisture, high temperatures, fire, ionizing irradiation, and mechanical bending. In this work, for the first time, lead-free double perovskite Cs2AgBiBr6 is utilized for environmentally robust memristors, enabling highly efficient information storage. The memory performance of the typical indium-tin-oxide/Cs2AgBiBr6/Au sandwich-like memristors is retained after 1000 switching cycles, 105 s of reading, and 104 times of mechanical bending, comparable to other halide perovskite memristors. Most importantly, the memristive behavior remains robust in harsh environments, including humidity up to 80%, temperatures as high as 453 K, an alcohol burner flame for 10 s, and 60Co γ-ray irradiation for a dosage of 5 × 105 rad (SI), which is not achieved by any other memristors and commercial flash memory techniques. The realization of an environmentally robust memristor from Cs2AgBiBr6 with a high memory performance will inspire further development of robust electronics using lead-free double perovskites.
关键词： lead free,resistive random access memory,memory,double perovskite,memristors
更新于2025-09-11 14:15:04
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The new ordered double perovskite SrLaCuIrO6
摘要： The new fully rock-salt ordered Ir5+ double perovskite SrLaCuIrO6 was synthesized, and its structural, magnetic and electronic properties were investigated. The compound crystallizes tetragonally (space group I4/m). The Cu2+ cation leads to strong Jahn-Teller distortion of the CuO6 octahedra. The compound shows semiconducting behavior with an estimated band gap of approximately 0.2 eV. At around 10 K a magnetic transition is observed.
关键词： D. Magnetic properties,E. High-temperature synthesis,A. Double perovskite,D. Jahn-Teller distortion
更新于2025-09-10 09:29:36
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Dopants Control of Electron-Hole Recombination in Cesium-Titanium Halide Double Perovskite by Time Domain Ab Initio Simulation: Co-Doping Supersedes Mono-Doping
摘要： Using nonadiabatic (NA) molecular dynamics combined with time-domain density functional theory, we simulate electron-hole recombination in pristine and doped inorganic Pb-free double perovskite Cs2TiBr6. We show that replacing the titanium and/or bromine with silicon and/or chlorine extends the charge carrier lifetime. Importantly, dopants avoid deep traps despite they do not change the fundamental bandgap of Cs2TiBr6, they decrease the NA electron-phonon coupling and accelerate decoherence, arising from the reduced overlap of electron and hole wave functions as well as fast phonon modes induced by light dopants respectively, suppressing electron-hole recombination. More importantly, co-doping can reduce the formation energy of silicon and achieve higher doping concentration, potentially increasing the lifetime further. Our study suggests a rational strategy to reduce energy losses by co-doping in design of high performance all-inorganic Pb-free perovskite solar cells.
关键词： Co-doping,Electron-Hole Recombination,Mono-doping,Energy Conversion and Storage,Cesium-Titanium Halide Double Perovskite,Plasmonics and Optoelectronics,Time Domain Ab Initio Simulation,Dopants Control
更新于2025-09-10 09:29:36
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Photoluminescence Tuning in Novel Bi3+/Mn4+ Co-doped La2ATiO6:(A = Mg, Zn) Double Perovskite Structure: Phase Transition and Energy Transfer
摘要： Red-emitting phosphors are indispensable componans to achieve warm white light of phosphor-converted white light emitting diodes (pc-WLEDs). However, the luminous efficiency and stability for red phosphors are still a big challenge. In this work, we develop red-emitting double perovskite phosphors La2ATiO6:Bi3+, Mn4+ (A = Mg, Zn) (LAT: Bi3+, Mn4+) and disscuss the relationship between double perovskite phosphors structure and luminescence performance in detail. By designing Mg2+/Zn2+ cation substitution, It is noteworthy that the internal quantum efficiency (IQE) is remarkeblely enhanced beyond 20%. According to Rietveld refinement results for La2Mg(1-w)ZnwTiO6:Bi3+, Mn4+ (0 ≤ w ≤ 1) (LM(1-w)ZwT:Bi3+, Mn4+) solid solution, the proposed machanism of the spectral adjustment is ascribed to the appearance of phase transition, which results in a lower local structure symmetry of [LaO12] polyhedron and variation of crystal field environment for Mn4+. Notably, it is the first time to reveal the influence of local structure variation on luminescence tuning in double perovskite structure phosphors, which could offer a guidance to develop new phosphors system. In addition, we firstly succeed in realizing Bi3+/Mn4+ co-doped energy transfer in double perovskite structure phosphors. Due to the Bi3+→Mn4+energy transfer in LAT, red emission of Mn4+ ions could be dramatically enhanced. The energy transfer efficiency of LAT: Bi3+, Mn4+ eventually reaches exceed 90%. The IQE and thermal stability are all enhanced around 30% than non-codoped samples, respectively. These results indicate that Bi3+→Mn4+energy transfer strategy could play a pivotal role in developing highly efficient red-emitting phosphor. The performance of the fabricated pc-WLEDs devices indicates that LAT:Bi3+, Mn4+ could be a promising red phosphor for near ultraviolet (n-UV) based on warm pc-WLEDs.
关键词： pc-WLEDs,Bi3+/Mn4+ co-doped,double perovskite phosphors,energy transfer,Red-emitting phosphors
更新于2025-09-10 09:29:36
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Lead-Free Direct Bandgap Double Perovskite Nanocrystals with Bright Dual-Color Emission
摘要： Lead-free double perovskite nanocrystals (NCs), i.e. Cs2AgInxBi1?xCl6 (x = 0, 0.25, 0.5 0.75 and 0.9), that can be tuned from the indirect bandgap (x = 0, 0.25 and 0.5) to the direct bandgap (x = 0.75 and 0.9) are designed. Direct-bandgap NCs exhibit 3 times greater absorption cross-section, lower sub-bandgap trap states, and >5 times photoluminescence quantum efficiency (PLQE) compared with those observed for indirect bandgap NCs (Cs2AgBiCl6). A PLQE of 36.6% for direct bandgap NCs is comparable to those observed for lead-perovskite NCs in the violet region. Besides the band edge violet emission, the direct bandgap NCs exhibit bright orange (570 nm) emission. Density functional theory calculations suggesting forbidden transition is responsible for the orange emission, which is supported by time resolved PL and PL excitation spectra. The successful design of lead-free direct bandgap perovskite NCs with superior optical properties opens the door for high performance lead-free perovskite optoelectronic devices.
关键词： dual-color emission,direct bandgap,Lead-free,photoluminescence quantum efficiency,double perovskite nanocrystals
更新于2025-09-09 09:28:46
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Structural and Optical Properties of Cs2AgBiBr6 Double Perovskite.
摘要： We present a comprehensive study of the relationship between the crystal structure and optoelectronic properties of the double perovskite Cs2AgBiBr6, which has emerged as a promising candidate for photovoltaic. Based on single-crystal/powder X-ray diffraction and neutron powder diffraction, we have revealed the presence of a structural phase transition at Ts ～122K between the room-temperature cubic structure (space group F mˉ3m) and a new low-temperature tetragonal structure (I4/m). From reflectivity measurements we found that the peak exciton energy Eex ≈ 2.85 eV near the direct gap shifts proportionally to the tetragonal strain, which is consistent with the Eex being primarily controlled by a rotational degree of freedom of the crystal structure, thus by the angle Bi-Br-Ag. We observed the time-resolved photoluminescence kinetics and we found that, among the relaxation channels, a fast one is mainly present in the tetragonal phase, suggesting that its origin may lie in the formation of tetragonal twin domains.
关键词： optoelectronic properties,structural phase transition,double perovskite,photovoltaic,Cs2AgBiBr6
更新于2025-09-04 15:30:14