Chemical and Size Characterization of Layered Lead Iodide Quantum Dots via Optical Spectroscopy and Atomic Force Microscopy

A facile synthesis of Au-nanoparticles decorated PbI2 single crystalline nanosheets for optoelectronic device applications

This research communication presents a rapid and facile microwave-assisted synthesis of single crystalline nanosheets (SCNSs) of hexagonal lead iodide (PbI₂) decorated with Au nanoparticles, a potential optoelectronics material. Homogeneous low dimensional AuNP decoration in PbI₂ resulted in a new absorption band at ~604 nm and a shift in band gap from 3.23 to 3.00 eV. The significant enhancement of photoluminescent (PL) intensity observed in the AuNP-PbI₂ SCNSs is attributed to the coupling of the localized surface plasmon resonanzce of AuNP leading to improved excitation and emission rates of PbI₂-SCNSs in the region of the localized electromagnetic field. The Au-PbI₂ SCNSs display a compelling increment in photoconductivity, and its fabricated photodetector showed a stable and switchable photo-response. Due to ease of synthesis and enhanced photoconductivity along with appealing PL features, Au-PbI₂ SCNS has the potential to be used as a material of choice when fabricating an optoelectronic devices of high performance.

Tailoring the structural, morphological, optical and dielectric properties of lead iodide through Nd3+ doping

Hexagonal single crystal nanosheets of Nd³⁺ doped PbI₂ were effortlessly synthesized via microwave-assisted technique under a power of 700 W and in a duration of 15 minutes with a homogeneous morphology. X-ray diffraction, energy dispersive X-ray spectroscope, scanning electron microscope, FT-Raman, UV-Visible, photoluminescence and dielectric measurement were employed to study the product. High purity, single phase and presence of Nd³⁺ doping was confirmed. SEM study confirm the formation of nanorods and single crystal nanosheets of very few nanometers in size. Robust vibrational analysis has been carried out and the observed bands are assigned to the vibration modes of E₂¹, A₁¹, A₁², 2E₂¹ and 2E₁¹, respectively. These bands are red-shifted when compare to the corresponding bulk values which indicate relaxed nanostructure formation and occurrence of confinement effect. The thickness of the synthesized single crystal nanosheets are found to be in the range of ~20 to 30 nm. The energy band gap was calculated and found to be 3.35, 3.34, 3.42 and 3.39 eV for pure, 1, 3 and 5% Nd³⁺ doped lead iodide, respectively. The clear blue luminescence has been observed at 440 nm and 466 nm when excited at 250 nm and 280 nm respectively. Dielectric and ac electrical conductivity was also measured and discussed.

Structure-Tuned Lead Halide Perovskite Nanocrystals

Colloidally stable suspensions of lead halide perovskite nanocrystals are prepared from high-quality lead halide nanocrystal seeds. Perovskite nanocrystals with different layered crystal structures are reported. These systems are well suited for investigations of the intrinsic photophysics and spectroscopy of organic-inorganic metal halide perovskites.

Fabrication of CH₃NH₃PbI₃/PVP Composite Fibers via Electrospinning and Deposition

In our study, one-dimensional PbI₂/polyvinylpyrrolidone (PVP) composition fibers have been prepared by using PbI₂ and PVP as precursors dissolved in N,N-dimethylformamide via a electrospinning process. Dipping the fibers into CH₃NH₃I solution changed its color, indicating the formation of CH₃NH₃PbI₃, to obtain CH₃NH₃PbI₃/PVP composite fibers. The structure, morphology and composition of the all as-prepared fibers were characterized by using X-ray diffraction and scanning electron microscopy.

The S-hindered synthesis of PbSe/PbS nanosheets with enhanced electrochemical activities

A one-step synthesis of PbSe/PbS nanosheets for a Li ion battery.