3 research outputs found
Development of Superstrate CuInGaSe<sub>2</sub> Thin Film Solar Cells with Low-Cost Electrochemical Route from Nonaqueous Bath
Electrodeposition
of CuÂ(In,Ga)ÂSe<sub>2</sub> (CIGS) thin film is
an attractive approach for the development of highly efficient low-cost
solar cells. This work focuses on the effects of various electrodeposition
parameters on the growth and properties of CIGS layers. The films
deposited at −0.9 V tend to drive the growth of CIGS favoring
(112) crystal orientation, whereas the films deposited at −1.6
V show the orientation along (220)/(204). Interplanar distances corresponding
to (112) and (204/220) planes could be observed in the high resolution
transmission electron microscopy (HRTEM) images of the respective
films, confirming the dependence of the texture on the deposition
potential. Films with larger grains could be grown by maintaining
higher temperature (130 °C) during the deposition of layers.
X-ray photoelectron spectroscopy (XPS) confirmed the presence of Cu<sup>+</sup>, In<sup>3+</sup>, Ga<sup>3+</sup>, and Se<sup>2–</sup> valence states in the CIGS layers prepared at −0.9 and −1.6
V. The film deposited at −1.6 V with (220/204) orientation
showed high efficiency as compared to the film deposited at −0.9
V with (112) orientation. The observed solar cell parameters, measured
under illuminated condition of input power intensity 100 mW/cm<sup>2</sup>, were <i>V</i><sub>OC</sub> = 0.357 V; <i>J</i><sub>SC</sub> = 27 mA/cm<sup>2</sup>, FF = 44, and η
= 4.90; and <i>V</i><sub>OC</sub> = 0.460 V, <i>J</i><sub>SC</sub> = 34 mA/cm<sup>2</sup>, FF = 58, and η = 9.07
for the deposition potentials of −0.9 and −1.6 V, respectively<sub>.</sub
Hybrid Perovskite Quantum Nanostructures Synthesized by Electrospray Antisolvent–Solvent Extraction and Intercalation
Perovskites based on organometal
lead halides have attracted great
deal of scientific attention recently in the context of solar cells
and optoelectronic devices due to their unique and tunable electronic
and optical properties. Herein, we show that the use of electrospray
technique in conjunction with the antisolvent–solvent extraction
leads to novel low-dimensional quantum structures (especially 2-D
nanosheets) of CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>- and CH<sub>3</sub>NH<sub>3</sub>PbBr<sub>3</sub>-based layered perovskites with
unusual luminescence properties. We also show that the optical bandgaps
and emission characteristics of these colloidal nanomaterials can
be tuned over a broad range of visible spectral region by compositional
tailoring of mixed-halide (I- and Br-based) perovskites
Biofunctionalized Gadolinium-Containing Prussian Blue Nanoparticles as Multimodal Molecular Imaging Agents
Molecular
imaging agents enable the visualization of phenomena
with cellular and subcellular level resolutions and therefore have
enormous potential in improving disease diagnosis and therapy assessment.
In this article, we describe the synthesis, characterization, and
demonstration of core–shell, biofunctionalized, gadolinium-containing
Prussian blue nanoparticles as multimodal molecular imaging agents.
Our multimodal nanoparticles combine the advantages of MRI and fluorescence.
The core of our nanoparticles consists of a Prussian blue lattice
with gadolinium ions located within the lattice interstices that confer
high relaxivity to the nanoparticles providing MRI contrast. The relaxivities
of our nanoparticles are nearly nine times those observed for the
clinically used Magnevist. The nanoparticle MRI core is biofunctionalized
with a layer of fluorescently labeled avidin that enables fluorescence
imaging. Biotinylated antibodies are attached to the surface avidin
and confer molecular specificity to the nanoparticles by targeting
cell-specific biomarkers. We demonstrate our nanoparticles as multimodal
molecular imaging agents in an <i>in vitro</i> model consisting
of a mixture of eosinophilic cells and squamous epithelial cells.
Our nanoparticles specifically detect eosinophilic cells and not squamous
epithelial cells, via both fluorescence imaging and MRI <i>in
vitro</i>. These results suggest the potential of our biofunctionalized
Prussian blue nanoparticles as multimodal molecular imaging agents <i>in vivo</i>