scholarly journals Photoelectrochromic Devices with Enhanced Power Conversion Efficiency

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2565
Author(s):  
Alexandros Dokouzis ◽  
Dimitra Zoi ◽  
George Leftheriotis
Keyword(s):  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Tio2 Film ◽  
Chemical Treatment ◽  
Short Circuit ◽  
Power Conversion ◽  
Optical Performance ◽  
Visual Obstruction ◽  
Cover Ratio ◽  
New Devices

In the present work, we propose a new architecture for partly covered photoelectrochromic devices with a modified anode layout, so that the TiO2 film is deposited first on the substrate, covering a small part of its surface, followed by the WO3 film that covers the remaining device area. As a result, the TiO2 film can be subjected to the proper thermal and chemical treatment without affecting the electrochromic performance of the WO3 film. The proposed design led to photoelectrochromic (PEC) devices with a power conversion efficiency (PCE) four times higher than that of typical partly covered devices, with a measured maximum of 4.9%. This, in turn, enabled a reduction in the total area covered by the photovoltaic unit of the devices by four times (to 5% from 20%), thus reducing its visual obstruction, without affecting the depth, uniformity and speed of coloration. A detailed study of the parameters affecting the performance of the new devices revealed that, with the cover ratio decreasing, PCE was increasing. The photocoloration efficiency also exhibited the same trend for cover ratio values below 15%. Storage of the devices in short circuit conditions was found to accelerate optical reversibility without affecting their photovoltaic and optical performance.

scholarly journals High performance tandem organic solar cells via a strongly infrared-absorbing narrow bandgap acceptor

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhenrong Jia ◽  
Shucheng Qin ◽  
Lei Meng ◽  
Qing Ma ◽  
Indunil Angunawela ◽  
...  
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Organic Solar Cells ◽  
High Performance ◽  
Short Circuit ◽  
Power Conversion ◽  
High Power Conversion Efficiency ◽  
Device Structure ◽  
Narrow Bandgap

AbstractTandem organic solar cells are based on the device structure monolithically connecting two solar cells to broaden overall absorption spectrum and utilize the photon energy more efficiently. Herein, we demonstrate a simple strategy of inserting a double bond between the central core and end groups of the small molecule acceptor Y6 to extend its conjugation length and absorption range. As a result, a new narrow bandgap acceptor BTPV-4F was synthesized with an optical bandgap of 1.21 eV. The single-junction devices based on BTPV-4F as acceptor achieved a power conversion efficiency of over 13.4% with a high short-circuit current density of 28.9 mA cm−2. With adopting BTPV-4F as the rear cell acceptor material, the resulting tandem devices reached a high power conversion efficiency of over 16.4% with good photostability. The results indicate that BTPV-4F is an efficient infrared-absorbing narrow bandgap acceptor and has great potential to be applied into tandem organic solar cells.

Effect of temperature on organic Schottky barrier cells

1981 ◽  
Vol 59 (6) ◽  
pp. 727-732 ◽  
Author(s):  
Rafik O. Loutfy ◽  
Cheng-Kuo Hsiao
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Schottky Barrier ◽  
Conversion Efficiency ◽  
Organic Solar Cells ◽  
Short Circuit ◽  
Power Conversion ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Photovoltaic Properties

The effect of temperature on the photovoltaic properties of indium/metal-free phthalocyanine Schottky barrier solar cells was investigated in the range 260–350 K. In general, the short circuit photocurrent, Jsc, and fill factor, ff, increased with increasing temperature (in contrast to inorganic photocells). The device series resistance and open circuit photovoltage, Voc, decreased (similar to inorganic photocells) as temperature was raised. An increase in the overall power conversion efficiency, η, has been observed with increase of temperature. In the case of x-H2Pc, the power conversion efficiency increased by 2.5 times due to a temperature rise of 60 °C above ambient. Thus, for operation at temperatures above ambient, organic solar cells may offer a significant advantage over inorganic cells.Analysis of the variation of the photovoltage with temperature showed that the decrease in Voc is mainly due to variation injunction impedance, which is controlled by thermionic current at high temperature and ionized impurity at low temperature.

The effect of methyl ammonium chloride doping for perovskite solar cells on structure, crystallization and power conversion efficiency

2020 ◽  
pp. 2150096
Author(s):  
Jing Gao ◽  
Chujian Liao ◽  
Yanqun Guo ◽  
Difan Zhou ◽  
Zhigang Zeng ◽  
...  
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Surface Defects ◽  
Short Circuit ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Short Circuit Current ◽  
High Quality ◽  
Perovskite Layer

The perovskite membrane with large particle size, uniform coverage and high quality is the prerequisite for the preparation of efficient and stable perovskite solar cells. Various additives have been used to increase the grain size and improve the film morphology and crystal quality. In this paper, methylammonium chloride (MACl) was proposed to obtain high crystalline quality of [Formula: see text] perovskite absorption layer. The results show that the adding ammonium methyl chloride into the precursor of tricationic perovskite not only passivates surface defects to form high-quality and large-grain perovskite films, but also facilitates the formation of pure [Formula: see text]-phase [Formula: see text]. Meanwhile, the designed perovskite precursor solutions were used to fabricate mesoporous perovskite solar cells (PSCs). Owing to the perovskite layer consisting of optimized MACl doping, the short-circuit current density [Formula: see text] of PSCs reaches 23.81 mA/cm2, which is 2.73 mA/cm2 higher than the primary [Formula: see text] based on PSCs. The obtained power conversion efficiency (PCE) increases from 13.67% to 17.59%.

scholarly journals Donor-Acceptor Polymer Based on Planar Structure of Alkylidene-Fluorene Derivative: Correlation of Power Conversion Efficiency among Polymer and Various Acceptor Units

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2859
Author(s):  
Eui Jin Lee ◽  
Ho Jun Song
Keyword(s):  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Short Circuit ◽  
Power Conversion ◽  
Average Molecular Weight ◽  
Coupling Reaction ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Planar Structure ◽  
Quinoxaline Derivatives

This study synthesized a novel polymer, poly(alkylidene fluorene-alt-diphenylquinoxaline) (PAFDQ), based on a planar alkylidene-fluorene and a highly soluble quinoxaline derivative through the Suzuki coupling reaction. We designed a novel molecular structure based on alkylidene fluorene and quinoxaline derivatives due to compact packing property by the planar structure of alkyidene fluorene and efficient intra-molecular charge transfer by quinoxaline derivatives. The polymer was largely dissolved in organic solvents, with a number average molecular weight and polydispersity index of 13.2 kg/mol and 2.74, respectively. PAFDQ showed higher thermal stability compared with the general fluorene structure owing to its rigid alkylidene-fluorene structure. The highest occupied and lowest unoccupied molecular orbital levels of PAFDQ were −5.37 eV and −3.42 eV, respectively. According to X-ray diffraction measurements, PAFDQ exhibited the formation of an ordered lamellar structure and conventional edge-on π-stacking. The device based on PAFDQ/Y6-BO-4Cl showed the best performance in terms of short circuit current (9.86 mA/cm2), open-circuit voltage (0.76 V), fill factor (44.23%), and power conversion efficiency (3.32%). Moreover, in the PAFDQ/Y6-BO-4Cl-based film, the phase separation of donor-rich and acceptor-rich phases, and the connected dark domains, was observed.

Effect of Crystallinity on the Performance of P3HT/PC70BM/n-Dodecylthiol Polymer Solar Cells

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Nidal Abu-Zahra ◽  
Mahmoud Algazzar
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Polymer Solar Cells ◽  
Short Circuit ◽  
Power Conversion ◽  
Crystallization Rate ◽  
Short Circuit Current ◽  
Scanning Calorimetry ◽  
Avrami Model

In this research, n-dodecylthiol was added to P3HT/PC70BM polymer solar cells (PSCs) to improve the crystallinity of P3HT and enhance the phase separation of P3HT/PC70BM. Crystallinity of P3HT:PC70BM doped with 0–5% by volume of n-dodecylthiol was measured using X-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques. Both methods showed improvement in crystallinity, which resulted in improving the power conversion efficiency (PCE) of polymer solar cells by 33%. In addition, annealing at 150 °C for 30 min showed further improvement in crystallinity with n-dodecylthiol concentration up to 2%. The highest power conversion efficiency of 3.21% was achieved with polymer crystallites size L of 11.2 nm, after annealing at 150 °C for 30 min under a vacuum atmosphere. The smaller crystallite size suggests a shorter path of the charge carriers between P3HT backbones, which could be beneficial to getting a higher short circuit current in the devices made with the additive. Kinetics study of P3HT:PC70BM crystallinity using Avrami model showed a faster crystallization rate (1/t0.5) at higher temperatures.

Preparation Mico/Nano Composite Particles and their Applications for Dye-Sensitized Solar Cells

2011 ◽  
Vol 239-242 ◽  
pp. 202-205
Author(s):  
Ting Lung Chiang ◽  
Chuen Shii Chou ◽  
Der Ho Wu ◽  
Chin Min Hsiung
Keyword(s):  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Glass Substrate ◽  
Short Circuit ◽  
Power Conversion ◽  
Dye Sensitized Solar Cells ◽  
Composite Particles ◽  
Dry Coating ◽  
Working Electrode ◽  
Fto Glass

This study investigated the applicability of TiO2/Au (or TiO2/Ag) composite particles, which probably have the plasmon resonance effect, on FTO-glass substrate of the working electrode of a DSSC. The dry particle coating technique was utilized to coat the surfaces of TiO2 particle with nano-sized Au (or Ag) powder particles. A layer of TiO2/Au (or TiO2/Ag) composite particles was deposited on the FTO-glass substrate of the working electrode, and it was then sintered in a high-temperature furnace. The working electrode covered with a TiO2/Au (or TiO2/Ag) thin film was kept immersed in a solution of N-719 (Ruthenium) dye for 12 h. Finally, the DSSC was assembled, and the short-circuit photocurrent; the open-circuit photovoltage, and the power conversion efficiency η of DSSC were measured using a home-made I-V measurement system. This study also examined the effects of the mass ratio of TiO2 to Au (or Ag) and the duration of dry coating on the η of the DSSC. If the duration of dry coating is adequate, the η of the DSSC with TiO2/Au (or TiO2/Ag) composite particles increased with increase in the percentage of Au (or Ag) in the composite particles. Most importantly, this study shows that the power conversion efficiency η of the DSSC with a film of TiO2/Au (or TiO2/Ag) on the working electrode always exceeds that of the conventional DSSC due to presence of the Schottky barrier, which is probably created in the TiO2/Au (or TiO2/Ag) composite particle.

Dye-Sensitized Solar Cells Using Polymer Electrolytes Based on Poly(vinylidene fluoride-hexafluoro propylene) Nanofibers by Electrospinning Method

2008 ◽  
Vol 8 (9) ◽  
pp. 4889-4894 ◽  
Author(s):  
Sung-Hae Park ◽  
Ji-Un Kim ◽  
Seong-Yeop Lee ◽  
Won-Ki Lee ◽  
Jin-Kook Lee ◽  
...  
Keyword(s):  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Polymer Electrolytes ◽  
Vinylidene Fluoride ◽  
Short Circuit ◽  
Power Conversion ◽  
Polymer Concentration ◽  
Dye Sensitized ◽  
Electrospinning Method ◽  
Poly Vinylidene Fluoride

The dye-sensitized solar cell (DSSC) devices using polymer electrolytes based on electrospun poly(vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) nanofibers were fabricated and investigated the photovoltaic performances. The electrospun PVDF-HFP nanofibers were prepared by various parameters such as; polymer concentrations, applied voltages, and tip to collector distances (TCD) by the electrospinning method. The open circuit voltage (VOC), short circuit current (JSC), fill factor (FF), and overall power conversion efficiency (η) of DSSC devices using electrospun PVDF-HFP nanofibers were 0.7180–0.7420 V, 9.7200–10.8837 mA/cm2, 0.5610–0.6250, and 4.1700–5.0186%, respectively. When 15 wt% of polymer concentration, 14 kV of applied voltage, and 14 cm of TCD is applied to fabricate the PVDF-HFP nanofiber, the electrospun PVDF-HFP nanofiber should be the regular diameter of a nanofiber, the power conversion efficiency of the DSSC device reached 5.0186% as the best result.

Organic Sensitizers Containing Julolidine Moiety for Dye-Sensitized Solar Cells

2008 ◽  
Vol 8 (9) ◽  
pp. 4761-4766 ◽  
Author(s):  
Dong Wook Kim ◽  
Jin Joo Choi ◽  
Man Ku Kang ◽  
Yongku Kang ◽  
Changjin Lee
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Short Circuit ◽  
Power Conversion ◽  
Dye Sensitized Solar Cells ◽  
Open Circuit ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Organic Sensitizers

We prepared organic sensitizers (S1 and S2) containing julolidine moiety as a donor, phenyl or phenylene thiophene units as a conjugation bridge, and cyano acetic acid as an acceptor for dye sensitized solar cells. S1 exhibited two absorption maxima at 441 nm (ε = 26 200) and 317 nm (ε = 15 500) due to the π–π* transition of the dye molecule. S2 dyes with an additional thiophene unit showed the absorption maximum extended by 18 nm. DSSCs based on S1 dye achieved 2.66% of power conversion efficiency with 8.3 mA cm−2 of short circuit current, 576 mV of open circuit voltage, and 0.56 of fill factor. DSSCs using S2 dye with a longer conjugation attained only 1.48% of power conversion efficiency. The 0.21 V lower driving force for regeneration of the S2 dye compared to the S1 dye is one of the reasons for low conversion efficiency of the S2 dye.

Inkjet printing of CH3NH3PbI3 on a mesoscopic TiO2 film for highly efficient perovskite solar cells

2015 ◽  
Vol 3 (17) ◽  
pp. 9092-9097 ◽  
Author(s):  
Shao-Gang Li ◽  
Ke-Jian Jiang ◽  
Mei-Ju Su ◽  
Xue-Ping Cui ◽  
Jin-Hua Huang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Tio2 Film ◽  
Inkjet Printing ◽  
Power Conversion ◽  
Perovskite Solar Cells ◽  
Average Value ◽  
Structure And Morphology ◽  
Light Absorber

CH3NH3PbI3 is deposited as a light absorber on a mesoporous TiO2 film and the structure and morphology are investigated at different table temperatures and with various amounts of added CH3NH3Cl. The optimized device exhibits the highest power conversion efficiency of 12.3% with an average value of 11.2%.

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