Search results for " Solar cell"
showing 10 items of 309 documents
Synchrotron Radiation and Chemistry: Studies of Materials for Renewable Energy Sources
2014
We present an overview of selected applications of synchrotron radiation methods to topical chemical research. The analysis is limited to the studies on materials for renewable energy sources, focussing on topics peculiar to chemical research, such as reactivity and synthesis routes; in particular, the paper takes into account subjects having some relevance for the production and storage of energy based on hydrogen. Hydrogen production and storage are taken into account in the sections concerning: (i) Dye-sensitized solar cells, (ii) Metal-organic frameworks and (iii) Hydrides for hydrogen storage; production of energy by fuel cell devices is treated in (iv) Oxide ion and proton conductors …
How the formation of interfacial charge causes hysteresis in perovskite solar cells
2018
In this study, we discuss the underlying mechanism of the current-voltage hysteresis in a hybrid lead-halide perovskite solar cell. We have developed a method based on Kelvin probe force microscopy that enables mapping charge redistribution in an operating device upon a voltage- or light pulse with sub-millisecond resolution. We observed the formation of a localized interfacial charge at the anode interface, which screened most of the electric field in the cell. The formation of this charge happened within 10 ms after applying a forward voltage to the device. After switching off the forward voltage, however, these interfacial charges were stable for over 500 ms and created a reverse electri…
Multifunctional derivatives of dimethoxy-substituted triphenylamine containing different acceptor moieties
2020
This project has received funding from the Research Council of Lithuania (LMTLT), Agreement No. [S-LZ-19-2]. This research was funded by the Région Centre, the Tunisian ministry of research, University of Monastir and the French ministry of Higher Education and Research. J. Bouclé would like to thank the Sigma-Lim LabEx environment for financial supports, and the PLATINOM facility at XLIM laboratory regarding device fabrication and characterizations. DG acknowledges the Lithuanian Academy of Sciences for the financial support.
Recombination in Perovskite Solar Cells
2017
Trap-assisted recombination, despite being lower as compared with traditional inorganic solar cells, is still the dominant recombination mechanism in perovskite solar cells (PSCs) and limits their efficiency. We investigate the attributes of the primary trap assisted recombination channels (grain boundaries and interfaces) and their correlation to defect ions in PSCs. We achieve this by using a validated device model to fit the simulations to the experimental data of efficient vacuum-deposited p-i-n and n-i-p CH3NH3PbI3 solar cells, including the light intensity dependence of the open circuit voltage and fill factor. We find that, despite the presence of traps at interfaces and grain bounda…
Determination of electron and hole energy levels in mesoporous nanocrystalline TiO2 solid-state dye solar cell
2006
A study of a hybrid heterojunction solar cell based on nanocrystalline mesoporous TiO2 and the hole conductor spiro-OMeTAD (2,2′7,7′-tetrakis(N,N′-di-p-methoxyphenyl-amine)-9,9′-spiro-bifluorene) has been realized. Impedance and cyclic voltammetry techniques were used to measure the interfacial properties of the hybrid heterojunction and establish the energy levels of the solid-state electrolyte. It was observed that the energy levels of the organic hole transport material are changed when it forms a film deposited onto indium-doped tin oxide (ITO). Moreover, the HOMO level of the mono oxidized spiro-OMeTAD is well coupled with the HOMO level of the dye N719 (Ru(4,4′-dicarboxy-2,2′-bipyridy…
Structural and spectral properties of ZnO nanorods by wet chemical method for hybrid solar cells applications
2015
Abstract The synthesis of ZnO nanorods on transparent conducting oxides, Al doped ZnO seed layer on glass substrate (AZO) and indium tin oxide substrate (ITO) by using zinc nitrate hexahydrate (Zn (NO3)2·6H2O) and hexamethylenetetramine (HMT, (CH2)6N4 as raw materials is presented. The ZnO seed layer was fabricated by depositing an Al-doped ZnO thin film on glass substrate by sputtering. The effect of seeding on (AZO) and (ITO) substrate by using the wet chemical route growth of ZnO nanorods was investigated. The synthesized nanostructures of ZnO were characterized by X-ray diffraction (XRD), UV–vis absorption spectroscopy, scanning electron microscopy (SEM) and high-resolution transmission…
Colloidal plasmonic back reflectors for light trapping in solar cells.
2014
A novel type of plasmonic light trapping structure is presented in this paper, composed of metal nanoparticles synthesized in colloidal solution and self-assembled in uniform long-range arrays using a wet-coating method. The high monodispersion in size and spherical shape of the gold colloids used in this work allows a precise match between their measured optical properties and electromagnetic simulations performed with Mie theory, and enables the full exploitation of their collective resonant plasmonic behavior for light-scattering applications. The colloidal arrays are integrated in plasmonic back reflector (PBR) structures aimed for light trapping in thin film solar cells. The PBRs exhib…
Self-assembled silver nanoparticles for plasmon-enhanced solar cell back reflectors: correlation between structural and optical properties
2013
The spectra of localized surface plasmon resonances (LSPRs) in self-assembled silver nanoparticles (NPs), prepared by solid-state dewetting of thin films, are discussed in terms of their structural properties. We summarize the dependences of size and shape of NPs on the fabrication conditions with a proposed structural-phase diagram. It was found that the surface coverage distribution and the mean surface coverage (SC) size were the most appropriate statistical parameters to describe the correlation between the morphology and the optical properties of the nanostructures. The results are interpreted with theoretical predictions based on Mie theory. The broadband scattering efficiency of LSPR…
Suppression of Forward Electron Injection from Ru(dcbpy)2(NCS)2 to Nanocrystalline TiO2 Film As a Result of an Interfacial Al2O3 Barrier Layer Prepar…
2009
Subnanometer-thick Al2O3 barrier layers on nanocrystalline TiO2 film were prepared with atomic layer deposition (ALD). The method allowed variation of barrier thicknesses at atomic resolution also deep in nanoporous structures, which makes it a superior method as compared to, e.g., sol−gel techniques. In this letter we present results on the effect of Al2O3 barriers of various thicknesses on forward electron injection in dye-sensitized solar cells. A decrease in the amplitude of the oxidized Ru(dcbpy)2(NCS)2 dye absorption signal due to singlet injection was observed already after one deposition cycle that produces a discontinuous layer with nominal thickness of 1 A. More than two layer coa…
Enhancement of photoconversion efficiency in dye-sensitized solar cells exploiting pulsed laser deposited niobium pentoxide blocking layers
2015
Abstract Among all the photovoltaic technologies developed so far, dye-sensitized solar cells are considered as a promising alternative to the expensive and environmentally unfriendly crystalline silicon-based solar cells. One of the possible strategies employed to increase their photovoltaic efficiency is to reduce the charge recombination at the cell conductive substrate through the use of a compact blocking layer. In this paper, we report on the fabrication and characterization of dye-sensitized solar cells employing niobium pentoxide (Nb 2 O 5 ) thin film blocking layer deposited through the pulsed laser deposition technique on conductive substrates. The careful selection of the optimal…