Pressure-Induced Changes in the Phase Distribution and Carrier Dynamics of Quasi-Two-Dimensional Ruddlesden-Popper Perovskites.

Quasi-two-dimensional (quasi-2D) perovskites hold significant potential for diverse design strategies due to their tunable structures, exceptional optical properties, and environmental stability. Due to the complexity of the structure and carrier dynamics, characterization methods such as photoluminescence and absorption spectroscopy can observe but cannot precisely distinguish or identify the phase distribution within quasi-2D perovskite films or correlate phases with carrier dynamics. In this study, we used pressure to modulate the intralayer and interlayer structures of (PEA)CsPbBr quasi-2D perovskite films, investigating charge carrier dynamics.

Time-Resolved Dynamics of Metal Halide Perovskite under High Pressure: Recent Progress and Challenges.

Metal halide perovskites have garnered significant attention in the scientific community for their promising applications in optoelectronic devices. The application of pressure engineering, a viable technique, has played a crucial role in substantially improving the optoelectronic characteristics of perovskites. Despite notable progress in understanding ground-state structural changes under high pressure, a comprehensive exploration of excited-state dynamics influencing luminescence remains incomplete.

Exploring the Potential Applications of Lanthanide-Based Double Perovskite in Remote Pressure and Temperature Sensing.

Remote optical sensing with nondestructive, fast, and accurate detection capabilities is a powerful noncontact method widely used in natural, industrial, and biological fields. In this work, CsNaErCl double perovskite was synthesized via a hydrothermal method. The pressure-dependent photoluminescence (PL) lifetime of Er in the range of 0-20 GPa was investigated, demonstrating its potential for pressure monitoring.

Anomalous Dynamics of Defect-Assisted Phonon Recycling in Few-Layer MoWS.

Alloying has emerged as a new strategy to tune the function of 2D transition metal dichalcogenides (TMDCs). However, the lack of research on the electrical and structural properties of these alloys limits their practical applications. Here, femtosecond transient absorption spectroscopy with pump pulse tunability is performed to elucidate the ultrafast carrier dynamics in the few-layer MoWS prepared by the liquid phase exfoliation method.

Physical Insights on the Thermoelectric Performance of CsSnBr with Ultralow Lattice Thermal Conductivity.

This study has investigated the microscopic mechanisms of ultralow lattice thermal conductivity by the first-principles density functional theory. By solving the phonon Boltzmann equation iteratively, we find that the thermal conductivity of the lattice is abnormally low and that glass like heat transfer behavior occurs. Therefore, in addition to the contribution about the particle-like propagation to heat transport, the off-diagonal elements of the heat-flux operator through wave-like interbranch tunneling of phonon modes are also considered.

Transformation between the Dark and Bright Self-Trapped Excitons in Lead-Free Double-Perovskite CsNaBiCl under Pressure.

Understanding the relationships between the structure and the properties in lead-free double perovskites is significant for their applications in the optoelectronic field. Here the nonluminous CsNaBiCl crystal exhibits an unexpected broadband dual-color emission as the external pressure is increased to 6.77 GPa.

Piezochromic luminescence in all-inorganic core-shell InP/ZnS nanocrystals via pressure-modulated strain engineering.

Piezochromic materials alter their photoluminescent (PL) colors in response to the action of external force. Such materials have attracted much attention owing to their promising applications in pressure-sensing, optoelectronic memory and anticounterfeiting. However, almost all the reported piezochromic materials were limited to the organic matters or compounds containing organic components.

Ultrastability and color-tunability of CsPb(Br/I) nanocrystals in P-Si-Zn glass for white LEDs.

A series of CsPbBrxI3-x NC glasses, showing tunable emission (523-693 nm) controlled by different ratios of Br- and I-, were successfully prepared. The CsPbBrxI3-x NC glasses exhibited excellent optical properties and outstanding stability towards ambient conditions, water and heat.

Moderate fabrication and characterization of the microcrystalline SrCuO glass films with effective nonlinearities.

Since nonlinear optical materials used in the ultrafast all-optical switching is an important part for the modern optical technology, cuprates have been widely investigated for their specific Cu-O chain structure and intriguing optical properties. We present a new preparation method of microcrystalline SrCuO glass films on glass substrates combining spin-coating and co-sintering techniques. Then, the as-prepared samples were polished for different times to obtain microcrystalline SrCuO glass films with varying thickness.

Multicolour nitrogen-doped carbon dots: tunable photoluminescence and sandwich fluorescent glass-based light-emitting diodes.

The first use of the combination of ammonium citrate (AC) and ethylenediamine tetraacetic acid (EDTA) as coordinating precursors for the synthesis of highly fluorescent (quantum yield = 67%) multicolour nitrogen-doped carbon dots (CDs) is reported. Under UV light, these CDs emitted outstanding luminescence in colours from dark blue to red. Interestingly, a single component white-light CD point with high fluorescence efficiency was obtained by surface control.

Use of long-term stable CsPbBr perovskite quantum dots in phospho-silicate glass for highly efficient white LEDs.

We report the synthesis of CsPbBr QDs with great stability and high quantum yield in phospho-silicate glass, which was fabricated by using a heat-treatment approach, for white light emitting devices. QD glasses exhibited excellent photo- and thermal stability, and significantly prolonged the lifetime of light emitters under ambient air conditions.