Search results for "photovoltaicS"
showing 10 items of 178 documents
Thin-Film Photovoltaics 2013
2014
Thin-Film Photovoltaics 2011
2012
Thin-Film Photovoltaics 2014
2015
The interest toward alternative energy sources to fossil fuels (still the most convenient in terms of efficiency and cost) is current. Initiatives that seek to convert wind, geothermal energy, hydropower, marine, solar thermal energy, and photovoltaics or derived from biomass energy into other forms continue to involve several research groups. For example, the transfer from solar energy into electricity, which in turn can be used for water splitting and for the subsequent production of hydrogen, seems a major challenge to provide a sustainable contribution to the “Earth system” together with the realization of devices having high conversion efficiencies, low environmental impact, and low pr…
Efficient Wide-Bandgap Mixed-Cation and Mixed-Halide Perovskite Solar Cells by Vacuum Deposition
2021
Vacuum deposition methods are increasingly applied to the preparation of perovskite films and devices, in view of the possibility to prepare multilayer structures at low temperature. Vacuum-deposited, wide-bandgap solar cells based on mixed-cation and mixed-anion perovskites have been scarcely reported, due to the challenges associated with the multiple-source processing of perovskite thin films. In this work, we describe a four-source vacuum deposition process to prepare wide-bandgap perovskites of the type FA1-n Cs n Pb(I1-x Br x )3 with a tunable bandgap and controlled morphology, using FAI, CsI, PbI2, and PbBr2 as the precursors. The simultaneous sublimation of PbI2 and PbBr2 allows the…
A Very Low Band Gap Diketopyrrolopyrrole-Porphyrin Conjugated Polymer
2017
International audience; A porphyrin-diketopyrrolopyrrole-containing polymer (poly(porphyrin-diketopyrrolopyrrole) (PPDPP)) shows impressive molar absorption coefficients from lambda=300 to 1000 nm. The photophysical and structural properties of PPDPP have been studied. With PPDPP as the electron donor and [ 6,6]phenyl C-71 butyric acid methyl ester (PC71BM) as the electron acceptor, the bulk heterojunction polymer solar cell showed overall power conversion efficiencies of 4.18 and 6.44% for as-cast and two-step annealing processed PPDPP: PC71BM (1: 2) active layers, respectively. These results are quite impressive for porphyrin-containing polymers, especially when directly included in the p…
Plasmonic nanostructures for light trapping in thin-film solar cells
2019
Abstract The optical properties of localized surface plasmon resonances (LSPR) sustained by self-assembled silver nanoparticles are of great interest for enhancing light trapping in thin film photovoltaics. First, we report on a systematic investigation of the structural and the optical properties of silver nanostructures fabricated by a solid-state dewetting process on various substrates. Our study allows to identify fabrication conditions in which circular, uniformly spaced nanoparticles are obtainable. The optimized NPs are then integrated into plasmonic back reflector (PBR) structures. Second, we demonstrate a novel procedure, involving a combination of opto-electronic spectroscopic tec…
High voltage vacuum-deposited CH3NH3PbI3-CH3NH3PbI3 tandem solar cells
2018
The recent success of perovskite solar cells is based on two solid pillars: the rapid progress of their power conversion efficiency and their flexibility in terms of optoelectrical properties and processing methods. That versatility makes these devices ideal candidates for multi-junction photovoltaics. We report an optically optimized double junction CH3NH3PbI3–CH3NH3PbI3 tandem solar cell where the matched short-circuit current is maximized while parasitic absorption is minimized. The use of an additive vacuum-deposition protocol allows us to reproduce calculated stack designs, which comprise several charge selective materials that ensure appropriate band alignment and charge recombination…
Growth of gold tips onto hyperbranched CdTe nanostructures
2008
Energy and charge transfer in nanoscale hybrid materials.
2015
Hybrid materials composed of colloidal semiconductor quantum dots and π-conjugated organic molecules and polymers have attracted continuous interest in recent years, because they may find applications in bio-sensing, photodetection, and photovoltaics. Fundamental processes occurring in these nanohybrids are light absorption and emission as well as energy and/or charge transfer between the components. For future applications it is mandatory to understand, control, and optimize the wide parameter space with respect to chemical assembly and the desired photophysical properties. Accordingly, different approaches to tackle this issue are described here. Simple organic dye molecules (Dye)/quantum…
Donor/Acceptor Heterojunction Organic Solar Cells
2020
The operation and the design of organic solar cells with donor/acceptor heterojunction structure and exciton blocking layer is outlined and results of their initial development and assessment are reported. Under halogen lamp illumination with 100 mW/cm2 incident optical power density, the devices exhibits an open circuit voltage VOC = 0.45 V, a short circuit current density JSC between 2 and 2.5 mA/cm2 with a fill factor FF &asymp