Search results for "Solar cell"
showing 10 items of 410 documents
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) …
Impact of π-conjugation configurations on the photovoltaic performance of the quinoxaline-based organic dyes
2017
Abstract Three novel quinoxaline-based donor-π-acceptor type organic dyes were synthesized and explored as sensitizers in dye-sensitized solar cells (DSSCs). The impacts of various π-conjugation configurations which contain different quinoxaline derivatives on the absorption properties, electrochemical properties and photovoltaic performances, as well as theoretical calculations have been investigated systematically. The photovoltaic performances of these dyes were found to be highly relevant to the π-conjugated configurations. In particular, the DSSC based on the dye with 2,3-dioctylquinoxaline as the spacer exhibited the highest efficiency of 8.20% with a short-circuit photocurrent densit…
Plasmon-enhanced photocurrent in quasi-solid-state dye-sensitized solar cells by the inclusion of gold/silica core–shell nanoparticles in a TiO2 phot…
2013
Direct evidence of the effects of the localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs) in TiO2 photoanodes on the performance enhancement in quasi-solid-state dye-sensitized solar cells (DSCs) is reported by comparing gold/silica core–shell nanoparticles (Au@SiO2 NPs) and hollow silica nanoparticles with the same shell size of the core–shell nanoparticles. The Au nanoparticles were shelled by a thin SiO2 layer to produce the core–shell structure, and the SiO2 hollow spheres were made by dissolving the Au cores of the gold/silica core–shell nanoparticles. Therefore, the size and morphology of the SiO2 hollow spheres were the same as the Au@SiO2 NPs. The energy conver…
Impact of the position isomer of the linkage in the double D–A branch-based organic dyes on the photovoltaic performance
2014
Abstract Three organic dyes with double D–A system were synthesized and applied in the dye-sensitized solar cells. These dyes contain phenothiazine as an electron donor and cyanoacetic acid as an acceptor/anchor. Linkages were incorporated at the ortho-, meta- and para-positions and their impact on the performance of photovoltaic was observed. Among them, the dye with a para-position linkage exhibited the highest short-circuit photocurrent density (12.26 mA cm−2) and open-circuit photovoltage (756 mV), leading to the best overall efficiency (6.14%) due to better light harvesting capacity under standard global 1.5 AM conditions. Under similar measuring conditions the dyes with ortho and meta…
Electrodes for GaOHPc:PCBM/P3HT:PCBM bulk heterojunction solar cell
2012
Abstract The bulk heterojunction approach appears to be one of the most promising concepts of creating efficient, low cost and easily producible organic solar cells. For this purpose one of the best materials was regioregular poly-3-hexylthiophene (P3HT), which is widely used as a donor molecule and a hole transporter, with soluble fullerene derivative (PCBM) as an acceptor and electron transporter. The main drawback of this highly efficient blend is its limited spectral range, covering only a 350–650 nm spectral interval. So the main aim of the present work was to extend the spectral range of the cell up to 850 nm by adding a second bulk heterojunction layer of complementary absorption spe…
Photocurrent enhancement in thin a-Si:H solar cells via plasmonic light trapping
2014
Photocurrent enhancement in thin a-Si:H solar cells due to the plasmonic light trapping is investigated, and correlated with the morphology and the optical properties of the selfassembled silver nanoparticles incorporated in the cells' back reflector. © 2014 OSA.
Synthesis and photovoltaic performance of asymmetric di-anchoring organic dyes
2015
Abstract Two novel metal-free organic dyes bearing two asymmetric double donor–acceptor segments were synthesized. Their physical, optical, electrochemical properties and photovoltaic performances were investigated. Compared with the mono-anchoring dye containing single donor–acceptor chain, these new dyes exhibited a broader and much stronger absorption in the light wavelength ranging from 400 to 600 nm, showed higher IPCE values and short-circuit current density, which led to more efficient photovoltaic performance. The dye with triphenylamine and phenothiazine as two electron donors and two cyanoacrylic acids as two electron acceptors exhibited an impressive power conversion efficiency o…
Radiative and non-radiative losses by voltage-dependent in-situ photoluminescence in perovskite solar cell current-voltage curves
2020
Abstract The rapid development of perovskite solar cells has been based on improvements in materials and device architectures, yet further progress towards their theoretical limit will require a detailed study of the main physical processes determining the photovoltaic performance. Luminescence can be a key parameter for this purpose, as it directly assesses radiative recombination. We present steady-state absolute photoluminescence of an operating device at varying voltages as a tool to study the loss mechanisms in perovskite devices. The calibration to absolute photon numbers gives access to the variation of the relative radiative/non-radiative recombination weighted along the measured po…