All-inorganic lead halide perovskites (CsPbX3) have attracted extensive attention due to their outstanding optoelectronic properties; however, their practical applications are severely limited by structural instability and defect-induced nonradiative recombination. Herein, we report a kinetically controllable hot-injection strategy to synthesize Cu2+-doped CsPbI3 nanoplates (NPLs). By precisely regulating the injection timing and amount of hydroiodic acid, a critical balance nucleation and growth is established, enabling the formation of uniform NPLs. Structural analysis confirms successful incorporation of Cu2+ into the CsPbI3 lattice without phase transition, accompanied by slight lattice contraction. Importantly, Cu2+ doping does not significantly change the bandgap but effectively reduces defect density, as evidenced by decreased Urbach energy and prolonged carrier lifetime. As a result, the photoluminescence quantum yield is maximized at an optimal doping level of 10%, reflecting effective defect suppression. Time-resolved photoluminescence further reveals suppressed nonradiative recombination and improved carrier dynamics. Moreover, the doped NPLs exhibit significantly enhanced stability, retaining similar to 82% of their initial PL intensity after 20 days, compared to similar to 8% for pristine samples. Overall, this work provides an effective strategy for simultaneously improving the luminescence performance and environmental stability of perovskite nanomaterials through defect engineering.

One-dimensional (1D) CsPbI3 nanowires (NWs) are promising for nanoscale optoelectronic applications due to their strong quantum confinement and anisotropic charge-transport characteristics, yet their practical use is severely limited by high defect density and poor structural stability. Here, we report an intrinsic stabilization strategy for CsPbI3 NWs via controlled Y3+ doping. CsPbI3 nanocrystals with different Y3+ contents were synthesized by a hot-injection method and subsequently transformed into 1D NWs through a solvent-induced phase conversion process. Structural characterizations demonstrate that Y3+ ions substitutionally occupy Pb2+ sites, inducing slight lattice contraction without generating secondary phases. Importantly, Y3+ incorporation markedly suppresses nonradiative defect states and enhances optical performance. The CsPbI3 NWs with an optimal Y3+ doping level of 20% exhibit the highest photoluminescence (PL) intensity and a 3-fold increase in average exciton lifetime, from similar to 35 ns for pristine NWs to similar to 110 ns after doping. Temperature-dependent PL analysis reveals an increased exciton binding energy from 413.6 to 491.2 meV and an enhanced longitudinal optical phonon energy from 465.2 to 614.6 meV, indicating strengthened exciton confinement and improved thermal stability. Moreover, the 20% Y3+-doped CsPbI3 NWs retain approximately 90% of their initial PL intensity after 28 days of ambient exposure, whereas pristine NWs undergo rapid degradation. These results demonstrate that Y3+ doping enables effective lattice-level defect regulation and intrinsic stabilization of CsPbI3 NWs, providing a robust and quantitative design strategy for high-performance and long-lifetime perovskite optoelectronic devices.

High-performance gas-sensitive materials must exhibit improved resistance to moisture essential criterion for their effectiveness. In this work, monodisperse triangle MnO nanocrystals were synthesized through the hot injection method. Then, they were evenly spread across the reduced graphene oxide (rGO) surface in a uniform dispersion. The optimized MnO/rGO exhibited high sensitivity (Ra/Rg=47.0) and quick response, with a lower detection limit. Furthermore, it shows strong moisture resistance in a high-humidity environment (80 % relative humidity). The comprehensive wrapping of stearate ligands proved highly effective in preventing water vapor infiltration. This robust shielding significantly boosted the composite's hydrophobic nature, markedly enhancing its resistance to moisture. This approach offers a pioneering avenue for gas sensors to detect NO2 effectively at room temperature, even within high-humidity environments.

Lead halide perovskites have emerged as promising candidates for next-generation optoelectronic devices owing to their tunable bandgaps, high photoluminescence efficiency, and excellent carrier transport characteristics. Low-dimensional nanostructures, particularly nanowires (NWs) and nanoplatelets (NPLs), further enhance these properties through anisotropic charge transport and strong quantum confinement; however, direct morphology-dependent comparisons remain limited. Herein, CsPbBr3 NWs and NPLs were synthesized via a ligand-regulated hot-injection strategy that enables precise dimensional control by tuning ligand ratios. The NWs exhibit uniform one-dimensional (1D) geometry (similar to 9 nm diameter), whereas NPLs form similar to 5 nm-thick two-dimensional (2D) structures. Structural and optical analyses reveal morphology-dependent spectral responses in which NWs show exciton absorption and emission at 505/520 nm, while NPLs display pronounced blue-shifts (465/480 nm) due to enhanced vertical confinement. Time-resolved photoluminescence reveals significantly longer exciton lifetimes in NWs (88.06 ns) than NPLs (32.20 ns), indicating reduced defect density and superior radiative recombination characteristics. Femtosecond transient absorption confirms slower carrier trapping and prolonged hot-carrier relaxation in NWs. This comparative study establishes a direct structure-property relationship between 1D and 2D CsPbBr3 nanostructures, offering insight into morphology-guided design for lasers, single-photon emitters, and blue optoelectronic devices.

One-dimensional (1D) CsPbI3 nanomaterials with long carrier lifetimes, high carrier transport efficiencies, and anisotropic optical properties show promising applications in lasers and photodetectors. In this study, monodisperse Cs4PbI6 nanocrystals (NCs) (12.3 nm) were first synthesized by thermal injection. The addition of deionized water to this solution then induced the conversion of Cs4PbI6 NCs into CsPbI3 NCs, followed by their self-assembly into CsPbI3 nanorods (NRs) with controllable aspect ratios. This process leverages the high solubility of CsI in water, which drives the decomposition of Cs4PbI6 and the formation of CsPbI3 NCs, which subsequently self-assembled and fused into CsPbI3 NRs. CsPbI3 NRs synthesized under the optimal reaction conditions were characterized by uniform size and regular morphology, with a diameter of 12.4 nm and length of 52.5 nm. XRD analysis shows that these monodisperse CsPbI3 NRs, in contrast to 1D CsPbI3 nanomaterials synthesized by the conventional thermal injection method, possess a typical cubic phase (alpha-phase) structure and exhibit good red light emission properties. Due to kinetic limitations during rapid nucleation at the nanoscale, the system preferentially forms the metastable alpha-CsPbI3, characterized by a low nucleation barrier and strong structural inheritance, rather than the thermodynamically stable delta-phase. Compared with NRs obtained under other reaction conditions, the optimal CsPbI3 NRs demonstrate stronger fluorescence intensity and longer fluorescence lifetime. The CsPbI3 NRs synthesized under the optimal conditions (2 mL water, 5 min) exhibit a strong first exciton absorption peak at 450 nm, a narrow photoluminescence emission peak at 695 nm, a lifetime as high as 239.9 ns, and a higher exciton binding energy (72.5 meV), ensuring efficient exciton emission at room temperature. Compared with NRs obtained under other reaction conditions, these optimally synthesized NRs demonstrate stronger fluorescence intensity and longer fluorescence lifetime. This work presents a reliable method for the controlled synthesis of 1D alpha-CsPbI3 NRs, offering a theoretical and experimental foundation for the application of halide perovskite nanorods in high-performance optoelectronic devices.

This study presents the synthesis and characterization of Cs2NaBiCl6 nanocrystals (NCs) doped with varying concentrations of In3+ to improve their luminescent properties. Utilizing a colloidal solution method, we systematically varied the In3+ concentration to identify the optimal alloying level for enhancing the photoluminescence (PL) properties of the Cs2NaBiCl6 NCs. Structural analysis confirmed that the In-alloyed NCs maintained high crystallinity and a uniform cubic shape. The optical properties were significantly improved with the In3+ alloying, reaching a peak photoluminescence quantum yield (PLQY) at an In/(Bi + In) ratio of 0.7. This optimal alloying concentration led to a nearly 2-fold increase in the average exciton lifetime to 6.98 ns, indicating an enhanced self-trapped exciton generation and improved radiative recombination efficiency. Temperature-dependent PL spectra revealed that the Cs2NaBi0.30In0.70Cl6 NCs exhibited a higher exciton binding energy and longitudinal optical phonon energy compared to the undoped NCs, suggesting superior thermal stability and reduced nonradiative recombination pathways. Density functional theory (DFT) calculations were employed to elucidate the charge density distribution, highlighting significant charge localization at the In-Cl and Bi-Cl bonds, which is attributed to the enhanced charge mobility in the alloyed NCs. The findings of this research not only address the limitations of current lead-free perovskites but also establish In-alloyed Cs2NaBiCl6 NCs as a promising candidate for blue light-emitting devices. This work advances the development of environmentally friendly optoelectronic technologies.

Metal halide perovskites (MHPs) have emerged as prominent materials in optoelectronics due to their exceptional photoelectric conversion efficiency and tunable band structures. Traditional perovskite nanocrystal synthesis systems often employ oleic acid (OA) to accelerate the crystallization kinetics, which inadvertently hinders nanowire growth and morphology control. In this study, we adopted a dual-ligand system using oleylamine (OAm) and octylamine (OctAm) without preadding OA. By postinjecting a cesium oleate solution, we achieved precise control over Pb2+ ion release, enabling the controllable synthesis of cesium lead halide (CsPbBr3) nanowires (NWs) across 100-160 degrees C. This strategy yielded micrometer-scale NWs with tunable diameters (8.3-12.6 nm) and lengths reaching the microscale. Temperature-dependent optical studies revealed that elevated synthesis temperatures weakened quantum confinement effects, leading to systematic red-shifts in ultraviolet-visible (UV-vis) absorption (505-507 nm) and photoluminescence (PL) emission (516-518 nm) peaks. Concurrently, time-resolved PL measurements revealed a significant enhancement in carrier lifetime (24.72-91.99 ns), reflecting reduced nonradiative recombination pathways. Variable-temperature PL spectroscopy (80-300 K) demonstrates that CsPbBr3 NWs synthesized at 140 degrees C exhibit higher exciton binding energy (E b = 44.7 meV) and enhanced exciton-phonon coupling strength (Gamma OP = 46.48 meV) compared to samples prepared at 120 degrees C. These findings demonstrate that high-temperature synthesis confers superior thermal stability on CsPbBr3 NWs. Our work not only clarifies the critical role of amine ligands in modulating NW growth dynamics but also provides a robust framework for designing stable, high-performance, one-dimensional perovskite optoelectronic materials.

Lead-free double perovskite nanocrystals (NCs) have garnered significant attention due to their ability to address the toxicity and instability issues associated with lead-based perovskite NCs. Herein, we have successfully synthesized a series of Cs2AgBiBr6 NCs with varying concentrations of In3+ alloying, achieved through a colloidal solution method. These NCs consistently exhibit a monodisperse, uniform cubic morphology. By meticulously adjusting the alloying concentration of In3+, we have significantly enhanced the luminescence performance of Cs2AgBiBr6 NCs, achieving a maximum photoluminescence quantum yield of 14.69% at the optimal In3+ alloying concentration. Simultaneously, the exciton lifetime was markedly extended 4.6 times, greatly enhancing carrier dynamics. Temperature-dependent photoluminescence spectroscopy analysis further confirms that postalloying with In3+, the NCs not only exhibit strong Coulombic forces and high thermal stability but also significantly reduce nonradiative transition processes. Moreover, density functional theory calculations reveal that In3+ alloying leads to a redistribution of charge density, profoundly affecting the electronic structure and subsequently enhancing the carrier mobility. Therefore, this study not only provides valuable insights into the role of In3+ alloying in enhancing the luminescence performance of double perovskite NCs but also opens up potential application prospects for optoelectronic devices in the future.

Lead-free halide double perovskite nanocrystals (NCs) are promising alternatives to lead-based perovskites, offering eco-friendly composition, robust intrinsic thermodynamic stability, and tunable optoelectronic properties.

CsPbI3 nanocrystals (NCs) are highly promising for optoelectronic applications due to their excellent photoluminescence quantum yield (PLQY), adjustable emission wavelength, and high color purity. However, their poor stability poses significant challenges for practical applications and further development. In this study, we synthesized CsPbI3 NCs doped with copper ions (Cu2+) using a hot-injection method, with Cl- ions effectively passivating surface defects. We then examined the effects of varying Cu2+ doping levels (0%, 5%, 10%, and 15%) on their properties. X-ray diffraction (XRD) analysis showed that Cu2+ doping caused the main diffraction peak to shift to higher angles, indicating the successful substitution of Pb2+ by Cu2+ in the crystal structure. Specifically, doping with 10% Cu2+ increased the photoluminescence quantum efficiency from 53.88% to 94.24% and extended the exciton lifetime from 36.60 to 50.26 ns. From 17.72 to 50.11 ps, the bleach recovery rate for Cu2+-doped samples is approximately 25%, while that for undoped samples is 28%. Additionally, the environmental stability of the NCs was greatly improved. This study highlights the potential of using transition metal ion doping to enhance the optoelectronic properties and stability of the photoluminescence quantum efficiency.

Monodisperse, small-sized NaYF4:Yb/Er@NaYF4 upconversion nanocrystals with a core-shell structure have been controllably prepared via a facile colloidal synthesis method and incorporated as a multifunctional layer on top of the TiO2 film in dye-sensitized solar cells (DSSCs). The unique bilayer hybrid photoanode exhibited enhanced relay efficiency, as the small-sized NaYF4:Yb/Er@NaYF4 nanocrystals infiltrated into the TiO2 film, effectively mitigating the effects of surface defects and ligands on electron recombination. The upconversion effect of the core-shell NaYF4:Yb/Er@NaYF4 nanocrystals converted lower-energy photons into high-energy visible photons, which were absorbed by the dye molecules, thereby broadening light absorption spectrum. Additionally, the light scattering and waveguide effects increased the optical path length through the multiple reflections, further enhancing light harvesting capabilities. Ultimately, with the optimal NaYF4:Yb/Er@NaYF4 nanocrystals, a photoelectric conversion efficiency of 9.24 % was achieved, marking a significant improvement of 17.9 % compared to NaYF4.

CsPbBr3 all-inorganic lead halide perovskite nanocrystals have significant applications due to their unique photoluminescence properties. However, their poor stability and easy decomposition in water significantly limit their practical applications. Encapsulating cesium lead halide perovskite quantum dots (PQDs) within a stable shell has been proven to be an effective strategy for enhancing their stability. However, traditional methods of coating PQDs via direct hydrolysis of silicon source often result in particle aggregation or alterations in the original morphology and optical properties of the PQDs. In this study, we employed maleic anhydride to trigger the transformation of Cs4PbBr6 into CsPbBr3 nanocrystals (NCs). Simultaneously, maleic anhydride reacts with surface oleylamine (OAm) ligands to form maleic acid, which replaces the conventional oleic acid (OA) and oleylamine as ligands and surfactants. A uniform CsPbBr3@SiO2 nanocomposite was obtained, with a core size of approximately 9nm and a shell thickness of about 15nm. The absorption peak was located at 520nm, with a full width at half maximum (FWHM) of around 25nm. After one hour of dispersion in water, the water-soluble CsPbBr3@SiO2 nanocomposite maintained a high level of luminescence, with a photoluminescence (PL) loss of only 30.1%. This approach enhances the affinity between PQDs and SiO2, improving the encapsulation efficiency of individual nanocrystals. This method not only prevents excessive hydrolysis and particle aggregation but also significantly enhances the water stability of CsPbBr3.

One-dimensional CsPbI3 nanocrystals (NCs) possess significant potential in laser and photodetection fields, due to their longer carrier lifetimes, more efficient carrier transport, and anisotropic optical properties. However, the rapid reaction kinetics of CsPbI3 NCs pose significant challenges for the controlled synthesis of one-dimensional CsPbI3 NCs. Here, a post-conversion method was used to synthesize monodispersed one-dimensional CsPbI3 nanowires (NWs) with controlled aspect ratios. The synthesized CsPbI3 NWs exhibited uniform morphology, with diameters of approximately 9.8nm and lengths of up to ca. 580nm. By controlling the amount of polar solvent acetone, the size of the CsPbI3 NRs could be well-regulated, achieving aspect ratios of approximately 4.2, 6.9, 8.3 and 58. In addition, CsPbI3 NWs were modified with 1-octadecanethiol (ODT), which improved the stability of the NWs. After 72hours of exposure to light, the morphology of the ODT-modified CsPbI3 NWs remained unchanged, and their photoluminescence (PL) lifetime increased from 35.5ns for unmodified NWs to 50.2ns for ODT-modified NWs. This work provides a reliable method for the controlled synthesis of one-dimensional CsPbI3 NWs with the enhanced stability, which expanded the application of one-dimensional CsPbI3 NWs in optoelectronic devices.

Double perovskite materials are promising lead-free alternatives due to their low toxicity and high stability. However, their large indirect bandgap limits optical performance. Morphology control offers an effective enhancement strategy. Here, cesium oleate (Cs-OA) and bromotrimethylsilane (TMS-Br) were injected into an oleic acid-free precursor. The OA present reacts with oleylamine (OAm) to form oleylammonium oleate (OAmH+·OA-), which, synergistically with OAm, enhances Ag+ and Bi3+ solubility. TMS-Br then provides bromide, triggering rapid nucleation of Cs2AgBiBr6 nanoclusters. Under thermodynamic control, these grow into uniform nanocrystals. Over time, multiple nanowires self-assemble and fuse into one-dimensional structures. Time-resolved photoluminescence shows a prolonged exciton lifetime of 19.0 ns, indicating low defect density. Temperature-dependent PL confirms a large exciton binding energy (61.1 meV), weak nonradiative recombination, and strong luminescence potential. The nanowires also exhibit excellent stability, retaining over 90% of their PL intensity after 90 days at room temperature.

Bismuth (Bi) is a promising anode material for lithium-ion batteries due to its high capacity. However, challenges such as low conductivity and significant volume expansion during charge cycles restrict its practical application. Metal-organic frameworks (MOFs), known for their controllable structure, hybrid inorganic-organic nature, large surface area, and high porosity, offer a solution to fix up above challenges. This study designs three-dimensional porous hollow spherical nanostructured bismuth-based MOF (Bi-MOF) by coordinating Bi3+ with terephthalic acid. The material features a functional spherical shell and internal pore structure that maintain open ion transport channels, abundant electrochemical sites, and a large contact area between electrolyte and electrode. This design accelerates ion/electron transport within the cavity, mitigating volume expansion during charge- discharge cycles and ensuring structural stability. As an anode material, Bi-MOF exhibits great electrochemical performance: retaining discharge capacities of 617.6 mAh g- 1 after 1000 cycles at 1 A g- 1 and 579.1 mAh g- 1 after 200 cycles at 0.1 A g- 1 . Coupled with LiFePO4 cathodes, the full-battery maintains 93.1 mAh g- 1 after 110 cycles at 1C. This work provides a train of thought to develop high-performance anode materials for enhanced lithium storage in lithium-ion batteries (LIBs) and validated the lithium storage mechanism of Bi-MOF.

High-purity CsPbBr 3 perovskite nanocrystals (NCs) and nanowires (NWs) had been synthesized using a hot-injection method within an amine-rich environment.

One-dimensional CsPbBr3 nanocrystals (NCs) possess significant potential in laser and photodetection fields due to their longer carrier lifetimes, more efficient carrier transport, and anisotropic optical properties. In recent years, Cs4PbBr6 has been employed to synthesize highly luminescent one-dimensional CsPbBr3 NCs; however, the poor stability of CsPbBr3 NCs produced by this method has limited their practical applications. In this study, CsPbBr3 nanorods (NRs) were prepared by removing CsBr from Cs4PbBr6 using a postsynthetic method. Water was added dropwise to Cs4PbBr6 NCs dispersed in a nonpolar solvent. Due to the high solubility of CsBr in water, the Cs4PbBr6 NCs rapidly converted into CsPbBr3 NCs. At this point, the addition of water-induced dipole-dipole interactions within the system drives the self-assembly of CsPbBr3 NCs into NRs. As the amount of water increased, the local concentration of CsPbBr3 NCs also rose, raising the probability of collisions between CsPbBr3 NCs and resulting in the formation of longer NRs. Subsequently, benzoic acid was introduced to replace the ligands removed along with CsBr. Due to the surface passivation effect of benzoic acid, the stability and photoluminescence performance of the CsPbBr3 NRs were significantly enhanced. The resulting CsPbBr3 NRs exhibited a fluorescence lifetime of 45.97 ns and achieved a high photoluminescence quantum yield (PLQY) of 94.2%. Stability tests showed that the ligand-passivated CsPbBr3 NRs retained 65% of their initial photoluminescence intensity after one month of storage in an open atmospheric environment.

Lead-free double perovskite nanocrystals (NCs) have garnered significant attention due to their non-toxicity and excellent stability, offering vast potential applications in the field of optoelectronics. They are considered promising substitutes for lead-based perovskite NCs. Herein, we successfully synthesized monodisperse, uniformly sized, cubic-shaped Cs2AgIn1-xBixCl6 (0 <= x <= 1) NCs via a simple hot injection approach. The Cs2AgInCl6 NCs exhibit a lower photoluminescence quantum yield (PLQY) of 3.9 % due to the presence of parity-forbidden transitions. However, with the introduction of Bi3+ alloying, the parity-forbidden transitions are broken, transforming into direct transitions allowed by parity. This transformation leads to efficient bright yellow emission, with the highest PLQY reaching up to 31.6 % (Cs2AgIn0.90Bi0.10Cl6 NCs). Adjusting the Bi3+ alloying concentration allows tuning the NCs band gap from 3.62 eV to 2.88 eV, and the exciton lifetime can be extended from 5.99 ns to 24.88 ns. Temperature-dependent photoluminescence spectra and density functional theory calculations indicate that Bi3+ alloying increases the exciton binding energy, weakens the electron-phonon coupling, and breaks parity-forbidden transitions. Moreover, Cs2AgIn0.90Bi0.10Cl6 NCs display outstanding stability under ambient conditions, laying a solid foundation for their applications in optoelectronics. The results of this study open a new pathway to enhance the optical performance of lead-free double perovskite nanomaterials.

Lead-free double perovskite nanocrystals (NCs) have emerged as a promising candidate in the optical field, owing to their non-toxic, good moist heat and chemical stability. However, their poor optical properties limited their application. To improve the optical properties of lead-free double perovskite NCs, metal ion doping or alloying had been suggested as a promising strategy. Here, we prepared monodisperse, uniformly sized, cubic morphology of Cs2AgBiCl6 NCs with different Na+ incorporation amounts via a simple hot-injection method. The Na+ incorporation broke the parity-forbidden transition by reducing the inversion symmetry of the electron wave function at the Ag site, which changed the parity of the self-trapped exciton wave function and thus allowed radiative recombination. As a result, the photoluminescence quantum yield (PLQY) of Na+-alloyed Cs2AgBiCl6 NCs (12.1%) was higher than that of Cs2AgBiCl6 NCs (2.4%), and the exciton lifetime of Na+-alloyed Cs2AgBiCl6 NCs increased to 36.98 ns from 17.58 ns for Cs2AgBiCl6 NCs. By adjusting the amount of Na+ incorporation, the band gap of Cs2AgBiCl6 NCs can be significantly tuned from ∼2.90 eV to ∼3.50 eV. Furthermore, the temperature-dependent photoluminescence spectra indicated that the Na+-alloyed Cs2AgBiCl6 NCs possessed higher longitudinal optical phonon energy and exciton binding energy compared to Cs2AgBiCl6 NCs. This suggested that there were strong exciton-phonon interactions during exciton recombination, a reduced probability of non-radiative processes, and excellent thermal stability. It offers a promising strategy for improving the optical properties of lead-free double perovskite NCs, and have the potential to replace traditional lead halide perovskite NCs in future optoelectronic applications.