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

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 54 ◽  
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.

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

2018 ◽  
Vol 9 ◽  
pp. 1802-1808 ◽  
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.

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

2017 ◽  
Vol 13 ◽  
pp. 863-873 ◽  
Author(s):  
Vinila N Viswanathan ◽  
Arun D Rao ◽  
Upendra K Pandey ◽  
Arul Varman Kesavan ◽  
Praveen C Ramamurthy
Keyword(s):  
Molecular Orbital ◽  
Architectural Design ◽  
Density Functional ◽  
Short Circuit ◽  
Energy Levels ◽  
Photovoltaic Performance ◽  
Hole Mobility ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Lowest Unoccupied Molecular Orbital

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.

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

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1752 ◽  
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.

Novel Linear and Hyperbranched Polythiophene Derivatives Containing Diketopyrrolopyrroles as Linking Groups

2015 ◽  
Vol 1771 ◽  
pp. 213-219
Author(s):  
Sheng-Hsiung Yang ◽  
Chia-Hao Hsieh
Keyword(s):  
Fill Factor ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Power Conversion ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Photovoltaic Properties ◽  
Molecular Weights ◽  
Active Layers ◽  
Film State

ABSTRACTThe goal of this research is to synthesize novel linear and hyperbranched polythiophene derivatives containing diketopyrrolopyrrole (DPP) as linking groups, and to investigate thermal, optical, electrochemical, and photovoltaic properties of those derivatives. Polymers with high regioregularity were synthesized via the Universal Grignard metathesis polymerization. Those linear or hyperbranched polythiophenes containing DPP bridging moieties showed higher molecular weights and better thermal stability compared with normal P3HT. The UV-vis absorption spectra of the DPP-containing polymers are similar to that of P3HT in film state, while they show distinct attenuation in fluorescent emission. Finally, all polymers were blended with PC61BM and used as active layers for fabrication of inverted solar devices. The devices based on those DPP-containing polythiophenes revealed the open-circuit voltage (VOC) of 0.55–0.58 V, the short-circuit current (JSC) of 8.62–16.21 mA/cm2, the fill factor (FF) of 36–41%, and the power conversion efficiency (PCE) of 1.73–3.74%.

scholarly journals Synthesis of Cyano-Substituted Conjugated Polymers for Photovoltaic Applications

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 746 ◽  
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%.

Simultaneous Enhancement of Open-Circuit Voltage, Short-Circuit Current Density, and Fill Factor in Polymer Solar Cells

2011 ◽  
Vol 23 (40) ◽  
pp. 4636-4643 ◽  
Author(s):  
Zhicai He ◽  
Chengmei Zhong ◽  
Xun Huang ◽  
Wai-Yeung Wong ◽  
Hongbin Wu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Current Density ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Polymer Solar Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit

Fabrication of TiO2 Nanotubes Array by Anodization for DSSC

2013 ◽  
Vol 743-744 ◽  
pp. 920-925
Author(s):  
Hong Zhou Yan ◽  
Jun You Yang ◽  
Shuang Long Feng ◽  
Ming Liu ◽  
Jiang Ying Peng ◽  
...  
Keyword(s):  
Fill Factor ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
X Ray

TiO2 nanotubes array was fabricated by anodization. Effect of reaction duration on the morphology of TiO2 nanotube arrays was studied detailedly. The structure and morphology of the prepared nanotubes array was characterized by X-ray diffraction and scanning electron microscopy, respectively. The fabricated TiO2 arrays were peeled off and adhered to FTO glass with adhesive (mixture of tetrabutyl titanate and polyethylene glycol), then they were sintered at 450 for photoanode of DSSC. The photovoltaic performance of the prepared sample as the DSSC anode was investigated. An open circuit voltage of 0.69V and a short circuit current density of 7.78mA/cm2 were obtained, and the fill factor and the convert efficiency were 0.517 and 2.78%, respectively.

Effects of Deposition Parameters on the Structure and Photovoltaic Performance of Si Thin Films by Metal Induced Growth

2008 ◽  
Vol 1123 ◽  
Author(s):  
Peter T. Mersich ◽  
Shubhranshu Verma ◽  
Wayne A. Anderson ◽  
Rossman F. Giese
Keyword(s):  
Thin Films ◽  
Absorption Coefficient ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
Photovoltaic Properties ◽  
X Ray ◽  
Metal Induced Growth

AbstractA metal-induced growth (MIG) process was employed to deposit thin films of microcrystalline silicon (μc-Si) for solar cell applications. Due to different grain orientations of the crystals, the absorption coefficient of μc-Si is about 10 times higher than the absorption coefficient of single crystalline Si. The properties of the Si film were investigated resulting from variations in several parameters. A range of Ni and Co thicknesses were examined from 7.5 nm to 60 nm including combinations of the two, while the dc sputtering power was stepped up from 150 W to 225 W. The structure of the resulting film was studied using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS) and x-ray diffraction (XRD). SEM of the film revealed that 5 hr of Si deposition at 150 W yields a film thickness of 6.5 μm and a maximum grain size of about 0.6 μm. EDS data showed that at the middle of the Si film the atomic percentage of the Si was 99.17%. XRD data showed that the dominant crystal orientation is {220}. To characterize the photovoltaic properties of the μc-Si, Schottky photodiodes were fabricated. Ni alone as the seed layer resulted in ohmic behavior. With Co only, MIG formed a rectifying contact with open-circuit voltage (V∝). The combination of Co layered over Ni formed better thin films and gave a Voc of 0.24 V and short-circuit current density (Jsc) of 5.0 mA/cm2 since the Co prevents Ni contamination of the top of the grown Si layer.

scholarly journals Dependence of material properties and photovoltaic performance of triple cation tin perovskites on the iodide to bromide ratio

2019 ◽  
Vol 150 (11) ◽  
pp. 1921-1927 ◽  
Author(s):  
Stefan Weber ◽  
Thomas Rath ◽  
Birgit Kunert ◽  
Roland Resel ◽  
Theodoros Dimopoulos ◽  
...  
Keyword(s):  
Material Properties ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Open Circuit ◽  
X Ray Diffraction ◽  
X Ray

Abstract In this work, the influence of a partial introduction of bromide (x = 0–0.33) into MA0.75FA0.15PEA0.1Sn(BrxI1−x)3 (MA: methylammonium, FA: formamidinium, PEA: phenylethylammonium) triple cation tin perovskite on the material properties and photovoltaic performance is investigated and characterized. The introduction of bromide shifts the optical band gap of the perovskite films from 1.29 eV for the iodide-based perovskite to 1.50 eV for the perovskite with a bromide content of x = 0.33. X-ray diffraction measurements reveal that the size of the unit cell is also gradually reduced based on the incorporation of bromide. Regarding the photovoltaic performance of the perovskite films, it is shown that already small amounts of bromide (x = 0.08) in the perovskite system increase the open circuit voltage, short circuit current density and fill factor. The maximum power conversion efficiency of 4.63% was obtained with a bromide content of x = 0.25, which can be ascribed to the formation of homogeneous thin films in combination with higher values of the open circuit voltage. Upon introduction of a higher amount of bromide (x = 0.33), the perovskite absorber layers form pinholes, thus reducing the overall device performance. Graphic abstract

Simultaneous improvement of three parameters using a binary processing solvent system approach in as-cast non-fullerene solar cells

2019 ◽  
Vol 7 (45) ◽  
pp. 25978-25984 ◽  
Author(s):  
Guoming Qin ◽  
Lianjie Zhang ◽  
Dong Yuan ◽  
Haiying Jiang ◽  
Wei Tang ◽  
...  
Keyword(s):  
Solar Cells ◽  
System Approach ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Solvent System ◽  
Open Circuit ◽  
Binary Solvent

A binary solvent approach simultaneously improves the open-circuit voltage, short-circuit current, and fill factor, and finally elevates the as-cast photovoltaic performance.

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