Mina Guli

Preparation and characterisation of TiO2 nanorod and nanotube films as photoanodes for dye-sensitised solar cells

TiO2 nanorod arrays are successfully synthesised on the transparent conductive fluorine-doped tin oxide glass through a facile one-step solvothermal route without any surfactant and template, TiO2 nanotube arrays were obtained through acid etching afterwards. Dye-sensitised solar cells based on these two different one-dimensional TiO2 photoelectrodes show the power conversion efficiency of 1.68 and 3.89% for nanorod and nanotube cells, respectively. The nanotube cell has better photoelectric performance than nanorod cell because of lower recombination, faster electron transformation, higher specific surface area for adsorbing more dye molecules and superior light scattering capacity for boosting the light-harvesting efficiency.

Fabrication of photoluminescent hybrid protein crystals of lysozyme and bromophenol blue

Abstract Hybrid protein crystals exhibiting enhanced photoluminescence were obtained by incorporation of bromophenol blue dye molecules within the organized solvent channels of cross-linked lysozyme single crystals. From the FT-IR, TEM, EDX, UV–Vis, and confocal characterization, we show that the BpB dye is inside the solvent channels of the crystals which has been bound up with the Trp62 and Trp108 residues of the protein.

Optical performance of mesostructured composite silica film loaded with organic dye.

A mesoporous composite silica film loaded with organic dye has been successfully synthesized by a solgel reaction process and a simple postgrafting method at room temperature. The composite film was characterized by x-ray diffraction, transmission electron microscopy, UV-Vis, photoluminescence (PL) spectra, and laser performance, and the results confirmed the existence of dyes in the channels of the silica film. A blue-shift and fluorescence property in the PL spectrum was observed from the composite film compared with that of dye molecules in C₂H₅OH solution. The spectrum narrowing phenomena has been observed when the composite film is pumped at λp=355  nm by a Nd:YAG pulsed laser. A narrower, higher peak was observed in emission spectra from the mesostructured composite silica film compared with the PL spectrum of dye in C₂H₅OH solution. There is a substantial reduction in the full width at half-maximum of the emitting light, which results in peaks with linewidths of 26 nm or more. This collapse of the emission spectrum is one of the signatures of the presence of amplified spontaneous emission.