Oleic acid (OA) modified zinc-blende cadmium selenium nanocrystals (NCs) with different diameters, 3-5 nm, have been prepared. We find that the morphology and fluorescent properties of the samples are related to the preparation conditions such as the chain-length and concentration of the cadmium precursor as well as the concentration of OA. The hybrid solar cells based on the obtained spherical CdSe NCs as an acceptor and Poly(2-methoxy-5-(2'-ethylhexoxy)-p-phenylenevinylene) (MEH-PPV) as a donor show an energy conversion efficiency (ECE) as high as 0.85%, three times higher than that reported before for spherical CdSe NCs/conjugated polymer hybrid solar cells. When poly(3-hexylthiophene) (P3HT) is used as the donor phase instead of MEH-PPV, the energy conversion efficiency increases up to 1.08%. The solar cell based on CdSe NCs/conjugated polymer has the potential to open up new production technologies for hybrid solar cells based on semiconductor NCs.

Blue-emitting YPO4:Ce3+ and green-emitting YPO4:Tb3+ and YPO4:Ce3+,Tb3+ phosphor particles were synthesized by coprecipitation method. Their structure and micromorphology have been analyzed by X-ray powder diffraction (XRD), FTIR spectra, and scanning electronic microscope (SEM). The transitions of Ce3+ 5d−4f and Tb3+ 5D4−7F J (J = 6−3) were detected, and the photoluminescence intensity of the Tb3+ increased on increasing the concentration of Ce3+. Finally, the energy-transfer process from Ce3+ to Tb3+ was investigated in YPO4:Ce3+,Tb3+ nanoparticles in detail. These nanoparticles can be potentially used as labels for biological molecules.

A novel and facile soft-chemical method has been proposed for the synthesis of Ag 3 PO 4 crystals with various new morphologies (branch, tetrapod, nanorod, triangular prism), and the morphological effect on the photocatalytic activity of the obtained Ag 3 PO 4 crystals has been investigated. It is demonstrated that the morphology of Ag 3 PO 4 crystals can be controlled by simply adjusting external experimental conditions such as static and ultrasonic conditions. Photocatalytic results indicate that the branched Ag 3 PO 4 crystal with porous structure shows the highest photocatalytic activity among these Ag 3 PO 4 crystals with multiform morphologies, and the photocatalytic rate constants of branched Ag 3 PO 4 are 2.8 and 4 times those of irregular spherical Ag 3 PO 4 for degradation of methylene blue (MB) and rhodamine B (RhB) dye solutions under visible light irradiation, respectively.

X-ray detectors with high performance, durability, and flexibility detectors are required for a wide range of applications in several fields, such as medical treatment (imaging, diagnostic radiology, etc.), nondestructive testing (radioscopic inspections, radiography testing, etc.), security and defense (luggage/body scanning systems, paper mail, etc.), nuclear and radiation industries (nuclear power plants, research reactors, users of nuclear gauges, etc.), and scientific research and development. [1]-[9] Thereof, indirect X-ray detectors are widely used for ordinary flat panel X-ray detection, among which scintillator is the most important factor affecting the detection performance. [10][11][12][13][14] Currently, the ideal scintillator should meet the following basic conditions: (i) good stopping power and excellent radiation absorption, [15]-[18] (ii) high photoluminescence (PL) with large Stokes shift and radioluminescence (RL) intensity, (iii) nontoxicity with environmentally stable, [19] (iv) easily manufactured and extendable to large-area flexible applications. [20,21] Among all, inorganic copper (I)-based metal halide semiconductors meeting all the above requirements are considered as promising candidates. In particular, zero-dimensional (0D) cesium copper chloride, Cs 3 Cu 2 Cl 5 , shows excellent photoelectric performance in ultraviolet photodetectors. [22] With isolated [Cu 2 Cl 5 ] 3dimers and Cs + ions, Cs 3 Cu 2 Cl 5 is expected to exhibit intriguing optical properties mainly derived from self-trapped excitons (STEs). Different from the narrow and rapid emission of free excitons and inter-band recombination, the emission of STEs is featured with broad spectra and large Stokes shifts. Generally, the STEs emission that occurs in Cs 3 Cu 2 Cl 5 originates from structural deformation of [Cu 2 Cl 5 ] 3− dimers. [23] At the time of photoexcitation, the Cu-Cl bonds elongate (shrink) on the equatorial plane but shrink (elongate) in the axial direction, which in turn causes the local structure change from a high symmetry to a low symmetry configuration.To further improve its photophysical characteristics, the diversified structural optimization in Cs 3 Cu 2 Cl 5 could offer deeper insights and more controlling knobs on STEs emission. Zero-dimensionalCs 3 Cu 2 Cl 5 exhibits intriguing optical properties, which can meet the basic requirements of ideal scintillator application. Here, green emitter Cs 3 Cu 2 Cl 5 nanosheets are successfully synthesized, and by doping with 2% potassium (K + ), their photoluminescence quantum yield (70.23% to 81.39%), radioluminescence intensity, and stability are improved. Further experimental and theoretical studies point out that: (1) K + brings the neighboring [Cu 2 Cl 5 ] 3− dimers groups closer, leading to lattice shrinkage and lower lattice constants; (2) such compact crystal structure results in stronger exciton-photon coupling and reduced phonon-electron coupling strength, which is beneficial to form self-trapped excitons and enhanced luminescence; (3) lower lattice ...

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The power conversion efficiency (PCE) of perovskite solar cells (PSCs) has exceeded 25%, showing great potential in the photovoltaic field. However, PSCs often show anomalous current density–voltage (J–V) hysteresis behavior in the forward and reverse scanning directions, which makes it impossible to accurately evaluate the performance of PSCs. Therefore, it is necessary to clearly understand the mechanism of hysteresis and suppress the hysteresis. Herein, the J–V hysteresis behavior in PSCs and strategies to suppress hysteresis is focused: first, the various factors that affect J–V hysteresis in PSCs are summarized. And the mechanism behind the various possible origins of hysteresis and the challenges encountered are explored. Then, the strategies to suppress or eliminate the hysteresis are summarized, including optimizing the perovskite light‐absorbing layer, improving the performance of the carrier transport layer and interface engineering. Finally, insights on the future development of the hysteresis are also provided.