Synthesis and Characterization of Polyaniline/Partially Phosphorylated Poly(vinyl alcohol) Nanoparticles

The polyaniline/partially phosphorylated poly（vinyl alcohol）（PANI/P-PVA） nanoparticles were prepared by the chemical oxidative dispersion polymerization of aniline monomer in 0.5 mol/L HC1 aqueous media with the partially phosphorylated poly（vinyl alcohol） （P-PVA） as the stabilizer and co-dopant. The PANI/P-PVA nanoparticles were characterized by transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FTIR）, thermal gravimetric analysis （TGA）, X-ray diffraction （XRD）, electrical conductivity measurements and re-dispersion stability testing. All the results were compared with the properties of the conventional polyaniline in the emeraldine salt form （PANI ES）. It was found that the feeding ratio of P-PVA obviously affected the morphology, re-dispersion stability and electrical conductivity of the PANI/P-PVA nanoparticles. When the feeding ratio of P-PVA ranged from 40 wt% to 50 wt%, the PANI/P-PVA nanoparticles showed spherical shape with good uniformity, significant re-dispersion stability in aqueous media and good electrical conductivity.

CsPbI_(2)Br epitaxial shell for efficient PbS quantum dot solar cells

Lead sulfide quantum dots(PbS QDs)are promising candidates for high-performance solar cells due to their tunable bandgaps and low-cost solution processing.However,low carrier mobility and numerous surface defects restrict the performance of the fabricated solar cells.Herein,we report the synthesis of novel PbS-perovskite core-shell QDs to solve the low carrier mobility problem of PbS QDs via a facile hot injection method.CsPbI_(2)Br shell enabled strain-free epitaxial growth on the surface of PbS QDs because of 98%lattice match.Our results demonstrate a significant improvement in the photoluminescence and stability of the synthesized PbS-CsPbI_(2)Br QDs upon shell formation,attributed to the effective suppression of surface defects by the epitaxial shell of CsPbI_(2)Br.As a result,the obtained solar cell based on PbS-CsPbI_(2)Br core-shell QD exhibits a power conversion efficiency(PCE)of 8.43%,two times higher than that of pristine PbS QDs.Overall,the construction of PbS-CsPbI_(2)Br core-shell structures represent a promising strategy for advancing the performance of PbS QDs-based optoelectronic devices.