Оптические свойства нанокомпозитов Fe-=SUB=-3-=/SUB=-O-=SUB=-4-=/SUB=-/CdSe/ZnS типа ядро-оболочка

The luminescent and magneto-optical properties of nanocomposites consisting of a superparamagnetic Fe3O4 core coated with a luminescent semiconductor CdSe layer, which, in turn, is surrounded by a passivating ZnS shell, are considered.

Efficient All-Inorganic CsPbBr3 Perovskite Solar Cells by Using CdS/CdSe/CdS Quantum Dots as Intermediate Layers

Highly efficient all-inorganic perovskite solar cells require a fast charge transfer from CsPbBr3 to TiO2 to reduce the recombination from trap states. Herein, we insert a CdS/CdSe/CdS quantum dot (QD) layer between the TiO2 and CsPbBr3 layers to fabricate all-inorganic perovskite solar cells. By tuning the thicknesses of the CdSe layer of CdS/CdSe/CdS QDs, the conduction band (CB) levels can be adjusted to -3.72~-3.87 eV. After inserting the QD intermediate layer, the energy offset between the CB of TiO2 and CsPbBr3 is reduced, thus leading to a charge transfer rate boost from 0.040×109 to 0.059×109 s−1. The power conversion efficiency (PCE) of the solar cell with QD intermediate layer achieves 8.64%, which is 20% higher than its counterpart without QDs.

Production and identification of highly photoconductive CdSe-based hybrid organic-inorganic multi-layer materials

Highly photoconductive thin multi-layers of new hybrid organic-inorganic semiconductors have been developed. They result by the combination of an inorganic semiconductor with ferrocene, a commercially available compound, applying the electrodeposition and spin coating techniques, introducing sodium oxalate as an additive in the electrolytic bath. The organic layer of the hybrid system is enveloped between two inorganic layers in a sandwich-like structure. The full characterization of the final products by XRD, SEM-EDAX, band gap and photoelectrochemical cell (PEC) measurements confirmed the development of the hybrid semiconducting system. The outer electrodeposited CdSe layer of the sandwich-like materials exhibits a definite hexagonal structure, whereas, as derived from the XRD and band gap data, the development of a new semiconducting compound has been confirmed. Thus, due to a synergic action, the three-layer materials present a remarkably improved photoresponse compared to that of the pure cubic CdSe electrodeposited in the presence of the oxalate additive as well as the three-layer hybrid CdSe-based products developed in our previous work in additive-free electrolytic baths. DOI: 10.21883/0000000000

Optical and cytotoxicity properties of water soluble type II CdTe/CdSe nanoparticles synthesised via a green method

ABSTRACTWe herein report the optical and cytotoxicity properties of highly luminescent water soluble mercaptopropanoic acid (MPA) capped CdTe/CdSe core shell nanoparticles (NPs). The synthesis of the CdTe/CdSe NPs was carried out via a simple, one pot and economical route, involving the use of greener materials under ambient environment in the absence of an inert atmosphere. The temporal evolution of the size and optical properties of the nanomaterials was investigated by varying the reaction time and stability of the as-synthesised material at pH 12. The as-synthesised nanomaterials were characterised using UV-vis absorption and photoluminescence (PL) spectroscopy. The nanoparticles obtained were of high quality with high absorption and emission features. Addition of Se precursor to produce CdSe layer on the CdTe NPs core surface resulted in significant red shirt of both the absorption and emission maxima. The stability study showed that the emission maximum peak positions and FWHM remain the same with increase in emission intensity for all the NPs during the aging period. The cytotoxicity assay showed very high cell viability for the CdTe/CdSe NPs produced at 7 h compared with those produced at 30 mins as the concentration increased from 0.1 to 60 ug/ml. The lower cytotoxicity at the higher reaction time was attributed to the higher stability of the material and hence lower release of Cd2+.