Publications by authors named "Wancai Li"

Chiral inorganic semiconductors with high dissymmetric factor are highly desirable, but it is generally difficult to induce chiral structure in inorganic semiconductors because of their structure rigidity and symmetry. In this study, we introduced chiral ZnO film as hard template to transfer chirality to CsPbBr film and PbS quantum dots (QDs) for circularly polarized light (CPL) emission and detection, respectively. The prepared CsPbBr/ZnO thin film exhibited CPL emission at 520 nm and the PbS QDs/ZnO film realized CPL detection at 780 nm, featuring high dissymmetric factor up to around 0.

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Due to their low viscosity, high mobility, and high element contents, supercritical fluids are important agents in the cycling of elements. However, the chemical composition of supercritical fluids in natural rocks is poorly understood. Here, we investigate well-preserved primary multiphase fluid inclusions (MFIs) from an ultrahigh-pressure (UHP) metamorphic vein of the Bixiling eclogite in Dabieshan, China, thus providing direct evidence for the components of supercritical fluid occurring in a natural system.

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Recently, a two-dimensional Dion-Jacobson (DJ) perovskite (AMP)PbI (AMP = 4-(aminomethyl)piperidinium) is emerging with remarkable Rashba effect and ferroelectricity. However, the origin of the giant Rashba splitting remains elusive and the current synthetic strategy via slow cooling is time- and power-consuming, hindering its future applications. Here, we report on an economical aqueous method to obtain (AMP)PbI crystals and clarify the origin of the giant Rashba effect by temperature- and polarization-dependent photoluminescence (PL) spectroscopy.

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Strain engineering provides an efficient strategy to modulate the fundamental properties of semiconducting structures for use in functional electronic and optoelectronic devices. Here, we report on how the strain affects the bandgap, optical anisotropy and stability of two-dimensional (2D) perovskite (BA)(MA)PbI (n = 1-3) microplates, using photoluminescence spectroscopy. Upon applying external strain, the bandgap decreases at a rate of -5.

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Low-dimensional lead halide perovskite materials are an emerging class of solution-processable semiconductors with promising potential applications in optoelectronic devices. Unfortunately, it is impossible to synthesize high-crystalline-quality low-dimensional perovskite single crystals without using chemotoxic solutions such as dimethylformamide/dimethyl sulfoxide or applying heating. Herein we report an economical and universal aqueous method to synthesize 2D layered and 1D chain perovskite single crystals at room temperature.

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Two-dimensional organic-inorganic perovskites have attracted considerable interest recently. Here, we present a systematic study of the temperature-dependent photoluminescence on phase pure (n-BA)(MA) Pb I ( n = 1-5) and (iso-BA)(MA) Pb I ( n = 1-3) microplates obtained by mechanical exfoliation. The photoluminescence peak position gradually changes from a red-shift for n = 1 to a blue-shift for n = 5 with an increase in temperature in the (n-BA)(MA) Pb I ( n = 1-5) series, while only a monotonous blue-shift has been observed for the (iso-BA)(MA) Pb I ( n = 1-3) series, which can be attributed to the competition between the thermal expansion interaction and electron-phonon interaction.

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The incorporation of chloride (Cl) into methylammonium lead iodide (MAPbI) perovskites has attracted much attention because of the significantly improved performance of the MAPbI-based optoelectronic devices with a negligible small amount of Cl incorporation. It is expected that the Cl incorporation in 2D perovskites with layered nature would be much more efficient and thus can greatly alter the morphology, optical properties, phase transition, and charge transport; however, studies on those aspects in 2D perovskites remain elusive up to date. Here, a one-pot solution method to synthesize the Cl-doped lead-free 2D perovskite (BA)SnI with various Cl incorporation concentrations is reported and how the Cl incorporation affects the morphology change, photoluminescence, phase transition, and charge transport is investigated.

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