The performance of perovskite solar cells is enhanced by modulating the Pb–O bond in a Lewis adduct via adding some strong Lewis bases into PbI2/DMF solutions.

We study the generation of correlated photon pairs via spontaneous four-wave mixing (SFWM) in a 15 cm long micro/nano-fiber (MNF). The MNF is properly fabricated to satisfy the phase-matching condition for generating the signal and idler photon pairs at wavelengths of about 1310 and 851 nm, respectively. Photon-counting measurements yield a coincidence-to-accidental ratio of 530 for a photon production rate of about 0.002 (0.0005) per pulse in the signal (idler) band. We also analyze the spectral information of the signal photons originating from SFWM and Raman scattering (RS). In addition to discovering some unique features of RS, we find the bandwidth of the individual signal photons is much greater than the calculated value for the MNF with homogeneous structure. Our investigations indicate the MNF is a promising candidate for developing the sources of nonclassical light and the spectral property of photon pairs can be used to noninvasively test the diameter and homogeneity of the MNF.

High quality CH3NH3PbI3 perovskite films without residual PbI2 are fabricated from the Lewis adduct of PbI2·xDMF through molecular exchange. The photovoltaic performances of the perovskite solar cells are thus improved significantly.

This paper describes a new adsorption material, carbon nanotube supported alumina, used for fluoride removal from water. The effects of calcination temperature, alumina loading and pH on fluoride removal capacity were investigated. The optimum calcination temperature for preparing the adsorbents is 450 °C and the largest adsorption capacity takes place at alumina loading of 30 wt%. The broad pH range of 6.0-9.0 with high adsorption capability suggests that carbon nanotube supported alumina have great potential applications in practice. The adsorption data at different pH were well fitted to the Freundlich isotherm. The kinetic studies show that the adsorption reaction of fluoride removal by carbon nanotube supported alumina can be described by a second order rate equation.

We demonstrate almost octave-spanning cascaded four-wave mixing (CFWM) in optical microfibers. Pumped by two synchronized picosecond lasers at about 850 nm, microfibers with a length of 10-20 cm can generate CFWM spanning from a few hundred nanometers to almost one octave, depending on the diameter of the microfibers and the detuning between the two pumps. CFWM in microfibers, which has the advantages of easy fabrication, highly efficient coupling, relatively short length, and easy integration with fiber systems, can be used for applications in widely tunable multiline phase-sensitive amplification, multiwavelength coherent sources, and ultrashort pulse synthesis.