Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

A series of low band gap, planar conjugated polymers, P1 (PFDTBT), P2 (PFDTDFBT) and P3 (PFDTTBT), based on fluorene and benzothiadiazole, was synthesized. The effect of fluorine substitution and fused aromatic spacers on the optoelectronic and photovoltaic performance was studied. The polymer, derived from dithienylated benzothiodiazole and fluorene, P1, exhibited a highest occupied molecular orbital (HOMO) energy level at −5.48 eV. Density functional theory (DFT) studies as well as experimental measurements suggested that upon substitution of the acceptor with fluorine, both the HOMO and lowest unoccupied molecular orbital (LUMO) energy levels of the resulting polymer, P2, were lowered, leading to a higher open circuit voltage and short circuit current with an overall improvement of more than 110% for the photovoltaic devices. Moreover, a decrease in the torsion angle between the units was also observed for the fluorinated polymer P2 due to the enhanced electrostatic interaction between the fluorine substituents and sulfur atoms, leading to a high hole mobility. The use of a fused π-bridge in polymer P3 for the enhancement of the planarity as compared to the P1 backbone was also studied. This enhanced planarity led to the highest observed mobility among the reported three polymers as well as to an improvement in the device efficiency by more than 40% for P3.

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A Quarterthiophene-Based Dye as an Efficient Interface Modifier for Hybrid Titanium Dioxide/Poly(3-hexylthiophene)(P3HT) Solar Cells

Polymers ◽

10.3390/polym11111752 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1752 ◽

Cited By ~ 3

Author(s):

Arumugam Pirashanthan ◽

Thanihaichelvan Murugathas ◽

Neil Robertson ◽

Punniamoorthy Ravirajan ◽

Dhayalan Velauthapillai

Keyword(s):

Titanium Dioxide ◽

Solar Cells ◽

Spectral Response ◽

Short Circuit ◽

Photovoltaic Performance ◽

Hole Mobility ◽

Short Circuit Current ◽

Acid Group ◽

Open Circuit ◽

Absorption Data

This work focused on studying the influence of dyes, including a thiophene derivative dye with a cyanoacrylic acid group ((E)-2-cyano-3-(3′,3′′,3′′′-trihexyl-[2,2′:5′,2′′:5′′,2′′′- quaterthiophene]-5-yl) acrylicacid)(4T), on the photovoltaic performance of titanium dioxide (TiO2)/poly(3-hexyl thiophene)(P3HT) solar cells. The insertion of dye at the interface improved the efficiency regardless of the dye used. However, 4T dye significantly improved the efficiency by a factor of three when compared to the corresponding control. This improvement is mainly due to an increase in short circuit current density (JSC), which is consistent with higher hole-mobility reported in TiO2/P3HT nanocomposite with 4T dye. Optical absorption data further revealed that 4T extended the spectral response of the TiO2/P3HT nanocomposite, which could also enhance the JSC. The reduced dark current upon dye insertion ensured the carrier recombination was controlled at the interface. This, in turn, increased the open circuit voltage. An optimized hybrid TiO2/P3HT device with 4T dye as an interface modifier showed an average efficiency of over 2% under-simulated irradiation of 100 mWcm−2 (1 sun) with an Air Mass 1.5 filter.

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Synthesis of Cyano-Substituted Conjugated Polymers for Photovoltaic Applications

Polymers ◽

10.3390/polym11050746 ◽

2019 ◽

Vol 11 (5) ◽

pp. 746 ◽

Cited By ~ 2

Author(s):

Mun Ho Yang ◽

Ho Cheol Jin ◽

Joo Hyun Kim ◽

Dong Wook Chang

Keyword(s):

Conjugated Polymers ◽

Molecular Orbital ◽

Polymer Solar Cells ◽

Short Circuit ◽

Energy Levels ◽

Coupling Reaction ◽

Short Circuit Current ◽

Open Circuit ◽

Strong Electron ◽

Photovoltaic Properties

Three conjugated polymers, in which the electron-donating (D) 5-alkylthiophene-2-yl-substitued benzodithiophene was linked to three different electron-accepting (A) moieties, i.e., benzothiadiazole (BT), diphenylquinoxaline (DPQ), and dibenzophenazine (DBP) derivative via thiophene bridge, were synthesized using the Stille coupling reaction. In particular, the strong electron-withdrawing cyano (CN) group was incorporated into the A units BT, DPQ, and DBP to afford three D–A type target polymers PB–BTCN, PB–DPQCN, and PB–DBPCN, respectively. Owing to the significant contribution of the CN-substituent, these polymers exhibit not only low-lying energy levels of both the highest occupied molecular orbital and the lowest unoccupied molecular orbital, but also reduced bandgaps. Furthermore, to investigate the photovoltaic properties of polymers, inverted-type devices with the structure of ITO/ZnO/Polymer:PC71BM/MoO3/Ag were fabricated and analyzed. All the polymer solar cells based on the three cyano-substituted conjugated polymers showed high open-circuit voltages (Voc) greater than 0.89 V, and the highest power conversion efficiency of 4.59% was obtained from the device based on PB-BtCN with a Voc of 0.93 V, short-circuit current of 7.36 mA cm−2, and fill factor of 67.1%.

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Steady Enhancement in Photovoltaic Properties of Fluorine Functionalized Quinoxaline-Based Narrow Bandgap Polymer

Molecules ◽

10.3390/molecules24010054 ◽

2018 ◽

Vol 24 (1) ◽

pp. 54 ◽

Cited By ~ 3

Author(s):

Zhonglian Wu ◽

Huanxiang Jiang ◽

Xingzhu Wang ◽

Lei Yan ◽

Wei Zeng ◽

...

Keyword(s):

Fill Factor ◽

Polymer Solar Cells ◽

Short Circuit ◽

Photovoltaic Performance ◽

Hole Mobility ◽

Short Circuit Current ◽

Open Circuit ◽

Promising Candidate ◽

Photovoltaic Properties ◽

Narrow Bandgap

To investigate the influence of fluoride phenyl side-chains onto a quinoxaline (Qx) unit on the photovoltaic performance of the narrow bandgap (NBG) photovoltaic polymers, herein, two novel NBG copolymers, PBDTT-DTQx and PBDTT-DTmFQx, were synthesized and characterized. 2-ethylhexylthiothiophene-substituted benzodithiophene (BDTT), 2,3-diphenylquinoxaline (DQx) [or 2,3-bis(3-fluorophenyl)quinoxaline (DmFQx)] and 2-ethylhexylthiophene (T) were used as the electron donor (D) unit, electron-withdrawing acceptor (A) unit and π-bridge, respectively. Compared to non-fluorine substituted PBDTT-DTQx, fluoride PBDTT-DTmFQx exhibited a wide UV-Vis absorption spectrum and high hole mobility. An enhanced short-circuit current (Jsc) and fill factor (FF) simultaneously gave rise to favorable efficiencies in the polymer/PC71BM-based polymer solar cells (PSCs). Under the illumination of AM 1.5G (100 mW cm−2), a maximum power conversion efficiency (PCE) of 6.40% was achieved with an open-circuit voltage (Voc) of 0.87 V, a Jsc of 12.0 mA cm−2 and a FF of 61.45% in PBDTT-DTmFQx/PC71BM-based PSCs, while PBDTT-DTQx-based devices also exhibited a PCE of 5.43%. The excellent results obtained demonstrate that PBDTT-DTmFQx by fluorine atom engineering could be a promising candidate for organic photovoltaics.

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Enhancement of the performance of CdS/CdTe heterojunction solar cell using TiO2/ZnO bi-layer ARC and V2O5 BSF layers: A simulation approach

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200213 ◽

2020 ◽

Vol 92 (2) ◽

pp. 20901

Author(s):

Abdul Kuddus ◽

Md. Ferdous Rahman ◽

Jaker Hossain ◽

Abu Bakar Md. Ismail

Keyword(s):

Solar Cell ◽

Short Circuit ◽

Photovoltaic Performance ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Heterojunction Solar Cell ◽

Back Surface ◽

Heterojunction Solar Cells

This article presents the role of Bi-layer anti-reflection coating (ARC) of TiO2/ZnO and back surface field (BSF) of V2O5 for improving the photovoltaic performance of Cadmium Sulfide (CdS) and Cadmium Telluride (CdTe) based heterojunction solar cells (HJSCs). The simulation was performed at different concentrations, thickness, defect densities of each active materials and working temperatures to optimize the most excellent structure and working conditions for achieving the highest cell performance using obtained optical and electrical parameters value from the experimental investigation on spin-coated CdS, CdTe, ZnO, TiO2 and V2O5 thin films deposited on the glass substrate. The simulation results reveal that the designed CdS/CdTe based heterojunction cell offers the highest efficiency, η of ∼25% with an enhanced open-circuit voltage, Voc of 0.811 V, short circuit current density, Jsc of 38.51 mA cm−2, fill factor, FF of 80% with bi-layer ARC and BSF. Moreover, it appears that the TiO2/ZnO bi-layer ARC, as well as ETL and V2O5 as BSF, could be highly promising materials of choice for CdS/CdTe based heterojunction solar cell.

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Direct AFM-based nanoscale mapping and tomography of open-circuit voltages for photovoltaics

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.171 ◽

2018 ◽

Vol 9 ◽

pp. 1802-1808 ◽

Cited By ~ 6

Author(s):

Katherine Atamanuk ◽

Justin Luria ◽

Bryan D Huey

Keyword(s):

Solar Cells ◽

Open Circuit Voltage ◽

Short Circuit ◽

Photovoltaic Performance ◽

Three Dimensional ◽

Short Circuit Current ◽

Open Circuit ◽

Photovoltaic Properties ◽

Order Of Magnitude ◽

Individual Grains

The nanoscale optoelectronic properties of materials can be especially important for polycrystalline photovoltaics including many sensor and solar cell designs. For thin film solar cells such as CdTe, the open-circuit voltage and short-circuit current are especially critical performance indicators, often varying between and even within individual grains. A new method for directly mapping the open-circuit voltage leverages photo-conducting AFM, along with an additional proportional-integral-derivative feedback loop configured to maintain open-circuit conditions while scanning. Alternating with short-circuit current mapping efficiently provides complementary insight into the highly microstructurally sensitive local and ensemble photovoltaic performance. Furthermore, direct open-circuit voltage mapping is compatible with tomographic AFM, which additionally leverages gradual nanoscale milling by the AFM probe essentially for serial sectioning. The two-dimensional and three-dimensional results for CdTe solar cells during in situ illumination reveal local to mesoscale contributions to PV performance based on the order of magnitude variations in photovoltaic properties with distinct grains, at grain boundaries, and for sub-granular planar defects.

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Photoactive Layer of DSSCS Based on Natural Dyes: A Study of Experiment and Theory

Journal of Nanomaterials ◽

10.1155/2015/139382 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 5

Author(s):

Yuanzuo Li ◽

Huixing Li ◽

Peng Song ◽

Chaofan Sun

Keyword(s):

Density Functional ◽

Short Circuit ◽

Dye Sensitized Solar Cells ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Natural Dyes ◽

Pheophytin A ◽

Charge Difference Density ◽

Forsythia Suspensa

Three natural dyes (Forsythia suspensa, Herba Violae, and Corn leaf) have been investigated as potential sensitizers for dye-sensitized solar cells. UV-vis absorption spectra reveal that three natural dyes mainly contain the compound of pheophytin a. Among three DSSCs, the highest photo electronic conversion efficiencyηis 0.96% with open circuit voltage (VOC) of 0.66 V, short circuit current density (ISC ) of 1.97 mA cm−2, and fill factor (ff) of 0.74. Theoretical time-dependent density functional theory and charge difference density are used to explore the nature of excited states. Results demonstrate that the first state is an intramolecular charge transfer (ICT) state, and electron injection could occur owing to the thermodynamically driving force.

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Benzothiadiazole Based Cascade Material to Boost the Performance of Inverted Ternary Organic Solar Cells

Energies ◽

10.3390/en13020450 ◽

2020 ◽

Vol 13 (2) ◽

pp. 450 ◽

Cited By ~ 1

Author(s):

Miron Krassas ◽

Christos Polyzoidis ◽

Pavlos Tzourmpakis ◽

Dimitriοs M. Kosmidis ◽

George Viskadouros ◽

...

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Short Circuit ◽

Photovoltaic Performance ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Fused Ring ◽

Electron Cascade ◽

First Time

A conjugated, ladder-type multi-fused ring 4,7-dithienbenzothiadiazole:thiophene derivative, named as compound ‘T’, was for the first time incorporated, within the PTB7:PC71BM photoactive layer for inverted ternary organic solar cells (TOSCs) realization. The effective energy level offset caused by compound T between the polymeric donor and fullerene acceptor materials, as well as its resulting potential as electron cascade material contribute to an enhanced exciton dissociation, electron transfer facilitator and thus improved overall photovoltaic performance. The engineering optimization of the inverted TOSC, ITO/PFN/PTB7:Compound T(5% v/v):PC71BM/MoO3/Al, resulted in an overall power conversion efficiency (PCE) of 8.34%, with a short-circuit current density (Jsc) of 16.75 mA cm−2, open-circuit voltage (Voc) of 0.74 V and a fill factor (FF) of 68.1%, under AM1.5G illumination. This photovoltaic performance was improved by approximately 12% with respect to the control binary device.

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HYBRID ORGANIC SOLAR CELLS BLENDED WITH CNTs

Surface Review and Letters ◽

10.1142/s0218625x15500729 ◽

2015 ◽

Vol 22 (06) ◽

pp. 1550072

Author(s):

SUDIP ADHIKARI ◽

HIDEO UCHIDA ◽

MASAYOSHI UMENO

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Short Circuit ◽

Photovoltaic Performance ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Photovoltaic Device ◽

Device Fabrication ◽

Walled Cnts

In this paper, composite carbon nanotubes (C-CNTs); single-walled CNTs (SWCNTs) and multi-walled CNTs (MWCNTs) are synthesized using an ultrasonic nebulizer in a large quartz tube for photovoltaic device fabrication in poly-3-octyl-thiophene (P3OT)/ n - Si heterojunction solar cells. We found that the device fabricated with C-CNTs shows much better photovoltaic performance than that of a device without C-CNTs. The device with C-CNTs shows open-circuit voltage (Voc) of 0.454 V, a short circuit current density (Jsc) of 12.792 mA/cm2, fill factor (FF) of 0.361 and power conversion efficiency of 2.098 %. Here, we proposed that SWCNTs and MWCNTs provide efficient percolation paths for both electron and hole transportation to opposite electrodes and leading to the suppression of charge carrier recombination, thereby increasing the photovoltaic device performance.

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Fabrication of Core-Shell Structured TiO2/MgO Electrodes for Dye-Sensitized Solar Cells

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.787.3 ◽

2015 ◽

Vol 787 ◽

pp. 3-7 ◽

Cited By ~ 2

Author(s):

S. Karuppuchamy ◽

C. Brundha

Keyword(s):

Solar Cells ◽

Short Circuit ◽

Photovoltaic Performance ◽

Dye Sensitized Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Core Shell ◽

Dye Sensitized ◽

The Core ◽

Sensitized Solar Cells

We demonstrated the construction and performance of dye-sensitized solar cells (DSCs) based on nanoparticles of TiO2coated with thin shells of MgO by simple solution growth technique. The XRD patterns confirm the presence of both TiO2and MgO in the core-shell structure. The effect of varied shell thickness on the photovoltaic performance of the core-shell structured electrode is also investigated. We found that MgO shells of all thicknesses perform as barriers that improve open-circuit voltage (Voc) of the DSCs only at the expense of a larger decrease in short-circuit current density (Jsc). The energy conversion efficiency was greatly dependent on the thickness of MgO on TiO2film, and the highest efficiency of 4.1% was achieved at the optimum MgO shell layer.

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Structural Behavior of Ni-Doped TIO2 Nanoparticles and its Photovoltaic Performance on Dye-Sensitized Solar Cell (DSSC)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.879.199 ◽

2014 ◽

Vol 879 ◽

pp. 199-205 ◽

Cited By ~ 1

Author(s):

Siti Nur Fadhilah Zainudin ◽

Markom Masturah ◽

Huda Abdullah

Keyword(s):

Short Circuit ◽

Anatase Phase ◽

Photovoltaic Performance ◽

Dye Sensitized Solar Cells ◽

Short Circuit Current ◽

Open Circuit ◽

Precipitation Method ◽

Ni Doping ◽

Dye Sensitized ◽

Co Precipitation

Different concentrations of Ni-doped anatase TiO2 nanoparticles were prepared by ice-bath co-precipitation method to examine the effects of various Ni2+ concentrations on the power exchange mechanism in photovoltaic performances of dye-sensitized solar cells (DSSC). X-ray powder diffraction (XRD) revealed a single anatase phase present in all samples together with three times reduction of particle size with the addition of Ni2+. Nanoparticle size exhibited better uniformity under scanning electron microscopy (SEM) with an increase of Ni2+ ions. Fourier Transform Infrared Spectroscopy (FTIR) confirmed the formation of Ti-O-Ni bonding due to sharpened and enhanced intensity of the bands in the range of 500-1000 cm-1 and 910-1030 cm-1. Ni2+ concentrations also increased both open-circuit voltage (Voc) and short-circuit current (Isc). The optimum concentration of Ni-doping obtained was at 0.075M of Ni which shows a maximum DSSC efficiency of 0.38%.

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