Search results for " Solar cell"
showing 10 items of 309 documents
Enhanced Efficiency of Organic Solar Cells by Thiol-capped Au-Nanoparticles
2015
In this work, we present a study on the effect of thiol-capped AuNPs of various sizesin an organic solar cell.AuNPs have been obtained by laser ablation in liquid solution[2], have been functionalized both with 2-naphthalenethiol and alkanethiol having different length. In addition to bulk heterojunction structures with optimized interpenetrating network of donors and acceptor domains, we have chosen to study planar heterojunctions (PHJs), consisting of three component thin films realized by sequential deposition of P3HT, AuNPs and PCBM from orthogonal solvents.
Enhanced power-conversion efficiency in organic solar cells incorporating polymeric compatibilizers
2018
Improved performance in flexible organic solar cells by using copolymeric phase-separation modulators
2018
One of the main problems related to the low performance of the organic solar cells (OSCs), concerns the low mobility of the materials constituting the heterojunction. Indeed, the poor charge transport in the active layer is the principal cause of a competition between separation and recombination of the photogenerated carriers. In this regard, a major obstacle to enhance OSCs efficiency is developing strategies to optimize the exciton dissociation and, consequently, the charge collection at the electrodes. Donor and acceptor systems must be well mixed on the length scale of 5 – 20 nm (exciton diffusion length) to meet the criteria for efficient exciton dissociation. In addition, the network…
Boron–nitrogen substituted dihydroindeno[1,2-b]fluorene derivatives as acceptors in organic solar cells
2019
The electrophilic borylation of 2,5-diarylpyrazines results in the formation of boron–nitrogen doped dihydroindeno[1,2-b]fluorene which can be synthesized using standard Schlenk techniques and worked up and handled readily under atmospheric conditions. Through transmetallation via diarylzinc reagents a series of derivatives were synthesized which show broad visible to near-IR light absorption profiles that highlight the versatility of this BN substituted core for use in optoelectronic devices. The synthesis is efficient, scalable and allows for tuning through changes in substituents on the planar heterocyclic core and at boron. Exploratory evaluation in organic solar cell devices as non-ful…
Experimental quantification of useful and parasitic absorption of light in plasmon-enhanced thin silicon films for solar cells application
2016
AbstractA combination of photocurrent and photothermal spectroscopic techniques is applied to experimentally quantify the useful and parasitic absorption of light in thin hydrogenated microcrystalline silicon (μc-Si:H) films incorporating optimized metal nanoparticle arrays, located at the rear surface, for improved light trapping via resonant plasmonic scattering. The photothermal technique accounts for the total absorptance and the photocurrent signal accounts only for the photons absorbed in the μc-Si:H layer (useful absorptance); therefore, the method allows for independent quantification of the useful and parasitic absorptance of the plasmonic (or any other) light trapping structure. W…
Unconventional materials for light-emitting and photovoltaic applications
2018
La motivación de este trabajo es el problema energético y éste ha sido abordado de dos maneras en esta tesis doctoral: promover un aumento de producción de energía mediante energías renovables junto con una reducción del consumo energético mediante el uso de sistemas más eficientes. Para este propósito, en esta tesis se han desarrollado dispositivos electroluminiscentes y fotovoltaicos novedosos de bajo coste y eficientes. En concreto, el trabajo se ha focalizado en el desarrollo de células electroquímicas emisoras de luz (LECs) emisoras en el rojo e infrarrojo cercano y en la mejora de su estabilidad. Así como en la fabricación de células solares de perovskita de alta eficiencia. Los dispo…
Semitransparent Perovskite Solar Cells with Multilayered Metal Top Electrodes for BIPVs and Tandem Applications
Semitransparent perovskite-based solar cells (ST-PSCs) are highly desired to be integrated into buildings as electricity-generating solar windows in the context of Building-Integrated Photovoltaics (BIPVs), as well as in tandem solar cells combined with other low-bandgap solar cells (e.g. silicon or CIGS) to give enhanced light-harvesting. To fabricate high-performance ST-PSCs, one key challenge is that of replacing the conventional opaque metal top electrodes with suitable transparent alternatives. Recently, dielectric/metal/dielectric (DMD) multilayer architectures have been shown to be suitable candidates as transparent top electrodes, exhibiting ideal characteristics such as mechanical …
Spatial inhomogeneities and defect structures in CIGS and CIS materials: An ab-initio based Monte Carlo study
2011
The chalcopyrite semiconductors CuIn 1−x Ga x Se 2 (CIGS) and CuInSe 2 (CIS) are excellent materials for high efficiency and low cost thin-film solar cells. This is due to the effective absorption of the solar spectrum and the inherent resilience to defects and composition fluctuations. Although the CIGS and CIS material in solar cells is highly inhomogeneous and exhibits a lot of different defects, the cell efficiencies are exceptionally high. If single crystalline absorbers are used, efficiencies are lower. Therefore, studying spatial inhomogeneities and defect structures is of great importance for understanding what supports and what diminishes the efficiency and robustness of the cells.…
Trilateral π-conjugation extensions of phenothiazine-based dyes enhance the photovoltaic performance of the dye-sensitized solar cells
2016
Abstract Two novel organic dyes TLEP-1 and TLEP-2 based on phenothiazine with trilateral π-conjugation extensions were designed and synthesized for dye-sensitized solar cells, where phenothiazine ring was linked with two phenyl moieties at 7- and 10-positions as the first and second π-conjugation extensions, and with furan or thiophene ring at 3-position as the third π-conjugation extension for TLEP-1 and TLEP-2, respectively. The influence of the π-conjugation extensions on the photovoltaic performance was evaluated. The cell based on TLEP-2 exhibits an impressive short-circuit photocurrent density of 14.87 mA cm−2, which is much higher than the cell based on the reference dye without π-co…
Conjugating pillararene dye in dye-sensitized solar cells
2021
Summary The improvement of open-circuit voltage (VOC) is a crucial goal to develop efficient dye-sensitized solar cells (DSSCs). Here, conjugating pillar[5]arene dyes (PPI and PPII) are designed, synthesized, and applied in DSSCs. The presence of pillar[5]arene moiety in the dyes inhibits the dye aggregation and charge recombination in the DSSCs, leading to the enhancement of VOC. PPI with a single D-π-A backbone and a pillar[5]arene moiety achieves a VOC of 715 mV, which is much higher than the reference dye (VOC of 674 mV) with the same D-π-A backbone but no pillar[5]arene moiety. PPII with 2 D-π-A backbones also achieves a VOC of 746 mV and a much higher short-circuit photocurrent (JSC) …