Recent Modeling of MDMO-PPV: PCBM Solar Cells versus Mixture Ratio, Electric Field and Incidence Angle with Hopping Model

It is a matter of controversy why excitons can efficiently dissociate into free carriers at an intrinsic polymer/fullerene interface. While extensive characterization is performed in the course of many reported experimental studies, correlation of performance and physical parameters among studies done in different laboratories is low, pointing out the need to address some aspects of BHJSC active materials that have received relatively some attention. In this paper, we discuss the modeling of MDMO-PPV/PCBM(Poly(2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylenevinylene)/ soluble C60 derivative, methanofullerene, [6,6]-phenyl C61-butyric acid methyl ester organic devices. In our approach, we apply two recent methods so called transfer matrix method and hopping model to calculate the exciton dissociation probability, and photocurrent density versus mixture ratio, electric field and angle of incidence. The results show that EDP (exciton dissociation probability) in solar cells without PEDOT-PSS (Poly (ethylendioxythiophene)-Poly(styrene sulfonic acid)) HTL hole transporting layer is better than the cells with additional layer in enhancing the performance of MDMO-PPV/PCBM solar cells. When the weight ratio of MDMO-PPV is less than 3:5 and 2:5 respectively, the best exciton dissociation probability, and photocurrent density of solar cell is obtained.

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Understanding of Photophysical Processes in DIO Additive-Treated PTB7:PC71BM Solar Cells

Crystals ◽

10.3390/cryst11091139 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1139

Author(s):

Xiaojun Su ◽

Rong Hu ◽

Guanzhao Wen ◽

Xianshao Zou ◽

Mengyao Qing ◽

...

Keyword(s):

Solar Cells ◽

Electric Field ◽

Time Scale ◽

Polymer Solar Cells ◽

Acid Methyl Ester ◽

Device Performance ◽

Operating Voltage ◽

Exciton Dissociation ◽

Carrier Recombination ◽

Dissociation Efficiency

1,8-diiodooctane (DIO) additive is an important method for optimizing the morphology and device performance of polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7)-based polymer solar cells. However, the effect of DIO additive on charge photogeneration dynamics of PTB7-based polymer solar cells is still poorly understood. In this work, the effect of DIO additive on the carrier photogeneration dynamics, as well as device performance of PTB7: [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) solar cells was studied. Bias-dependent photoluminescence (PL) experiments of a neat PTB7 device show that the exciton cannot be dissociated by the electric field in the device within the operating voltage range, but it can be effectively dissociated by the high electric field. PL and time-resolved PL studies show that DIO additive reduces the phase size of PTB7 in the blend film, resulting in an increased exciton dissociation efficiency. The carrier recombination processes were studied by transient absorption, which shows geminate carrier recombination was suppressed in the DIO-treated PTB7:PC71BM device in ultrafast time scale. The increased exciton dissociation efficiency and suppressed carrier recombination in ultrafast time scale play an important role for DIO-treated PTB7:PC71BM solar cells to attain a higher power conversion efficiency.

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Fullerene (PCBM) Modulated MEH-PPV Photoactive Material for Plastic Solar Cells

Materials Science Forum ◽

10.4028/www.scientific.net/msf.969.439 ◽

2019 ◽

Vol 969 ◽

pp. 439-443

Author(s):

Ishwar Naik ◽

Rajashekhar Bhajantri ◽

B.S. Patil ◽

Vinayak Bhat

Keyword(s):

Solar Cells ◽

Band Gap ◽

Polymer Matrix ◽

Low Cost ◽

Spectral Response ◽

Weight Ratio ◽

Acid Methyl Ester ◽

Research Problem ◽

Energy Difference ◽

Low Efficiency

Abstract.Plastic solar cells are promising devices in looking for low cost and flexible energy storing devices. Low efficiency is the main drawback of these cells in comparison with inorganic solar cells and hence the search for an efficient plastic solar cell has become a globally demanded research problem. In the present work we have used the modified fullerene [6,6]-Phenyl C61 butyric acid methyl ester (PCBM) as N type modulating probe on P type semiconducting polymer Poly[2-methoxy-5-(2’-ethylhexyloxy)-phenylenevinylene] (MEH-PPV). The donor MEH-PPV polymer matrix is modulated by adding PCBM in the weight ratio 1:3, 1:1 and 3:1 in Chloro-Benzene(CB) as the common solvent and glass-coated samples are prepared by solution cast method. Samples are analyzed by UV-VISIBLE spectroscopy by JASCO UV Vis NIR V 670 spectrometer. The effect of PCBM content on MEH-PPV is to broaden the spectral response of MEH-PPV. In other words the acceptor PCBM has tuned the band gap (energy difference between HOMO & LUMO) of the donor MEH-PPV. Spectral analysis revealed that 1:3 blend of MEH-PPV with PCBM has a wide spectral sensitivity for absorption. The band gap for each blend is determined using Tauc’s plot. Increased Fullerene content has decreased the band gap of the host polymer. We conclude that modified fullerene can effectively modulate the donor polymer matrix and 1:3 MEH-PPV: PCBM can act as a good photoactive material for solar cells. Absorption can be further enhanced by either dye sensitization or by metal oxide nanoparticle doping without increasing the thickness of the film. We have doped the optimized 1:3 blend with 20%, 40% & 60% of TiO2 nanoparticles wherein the absorption is enhanced with doping level. The increased absorption is attributed to the photocatalytic activity of the nanaoparticles embedded in the polymer matrix

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Ultrafast Charge Generation Enhancement in Nanoscale Polymer Solar Cells with DIO Additive

Nanomaterials ◽

10.3390/nano10112174 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2174

Author(s):

Tongchao Shi ◽

Zeyu Zhang ◽

Xia Guo ◽

Zhengzheng Liu ◽

Chunwei Wang ◽

...

Keyword(s):

Solar Cells ◽

Vibrational Relaxation ◽

Transient Absorption ◽

Polymer Solar Cells ◽

Acid Methyl Ester ◽

Free Charge ◽

Exciton Dissociation ◽

Charge Generation ◽

Carrier Generation ◽

Acid Methyl

We study the ultrafast photoexcitation dynamics in PBDTTT-C-T (P51, poly(4,8-bis(5-(2-ethylhexyl)-thiophene-2-yl)-benzo[1,2-b:4,5-b′]dithiophene-alt-alkylcarbonyl-thieno[3,4-b]thiophene)) film (~100 nm thickness) and PBDTTT-C-T:PC71BM (P51:PC71BM, phenyl-C71-butyric-acid-methyl ester) nanostructured blend (∼100 nm thickness) with/without DIO(1,8-diiodooctane) additives with sub-10 fs transient absorption (TA). It is revealed that hot-exciton dissociation and vibrational relaxation could occur in P51 with a lifetime of ~160 fs and was hardly affected by DIO. However, the introduction of DIO in P51 brings a longer lifetime of polaron pairs, which could make a contribution to photocarrier generation. In P51:PC71BM nanostructured blends, DIO could promote the Charge Transfer (CT) excitons and free charges generation with a ~5% increasement in ~100 fs. Moreover, the dissociation of CT excitons is faster with DIO, showing a ~5% growth within 1 ps. The promotion of CT excitons and free charge generation by DIO additive is closely related with active layer nanomorphology, accounting for Jsc enhancement. These results reveal the effect of DIO on carrier generation and separation, providing an effective route to improve the efficiency of nanoscale polymer solar cells.

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Improve Efficiency of Organic Solar Cell by Adding Dispersed ZnO Nanoparticles

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.842.43 ◽

2013 ◽

Vol 842 ◽

pp. 43-51

Author(s):

Yang Ming Lu ◽

Yu Fan Wu ◽

Lien Chung Hsu

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Active Layer ◽

Zno Nanoparticles ◽

Polymer Solar Cells ◽

Short Circuit ◽

Weight Ratio ◽

Acid Methyl Ester ◽

Well Being ◽

Organic Polymer

The poly (3-hexylthiophene) (P3HT) is a promising candidate material for using in polymer solar cells researches due to its good absorbance and stability. In this study, we present the electro-optical performance of organic polymer solar cells based on P3HT: [6,-phenyl-C61-butyric acid methyl ester (PCBM) with weight ratio of 1:1. We added ZnO nanoparticles into the blending of P3HT and PCBM to improve the performance of polymer solar cells. ZnO nanoparticles are very promising inorganic metal oxides for use in organic solar cells because of its low cost, nontoxicity, high reflectance and good electron transport properties. The morphology of polymer solar cell was improved due to the additional of ZnO nanoparticles. The effects of thermal annealing on the solar cell had been studied. The post-annealing shows significant improvement in the performance for solar cell. How to prevent ZnO nanoparticles to agglomerate is essential as they are added to the active layer of the solar cell. Well dispersed ZnO nanoparticles are obtained by using the methanol solvent. The best performances of the solar cell with short-circuit current density of 14.66 mW/cm2 and efficiency of 3.92% can be obtained after post-annealed with well being dispersed 1.3wt% ZnO nanoparticles in the active layer.

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Novel indolin-2-one-substituted methanofullerenes bearing long n-alkyl chains: synthesis and application in bulk-heterojunction solar cells

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.10.111 ◽

2014 ◽

Vol 10 ◽

pp. 1121-1128 ◽

Cited By ~ 6

Author(s):

Irina P Romanova ◽

Andrei V Bogdanov ◽

Inessa A Izdelieva ◽

Vasily A Trukhanov ◽

Gulnara R Shaikhutdinova ◽

...

Keyword(s):

Solar Cells ◽

Bulk Heterojunction ◽

Weight Ratio ◽

Acid Methyl Ester ◽

High Yield ◽

Solar Cell Performance ◽

Heterojunction Solar Cells ◽

Alkyl Chains ◽

Conversion Efficiencies ◽

Crystalline Domains

An easy, high-yield and atom-economic procedure of a C60 fullerene modification using a reaction of fullerene C60 with N-alkylisatins in the presence of tris(diethylamino)phosphine to form novel long-chain alkylindolinone-substituted methanofullerenes (AIMs) is described. Optical absorption, electrochemical properties and solubility of AIMs were studied. Poly(3-hexylthiophene-2,5-diyl) (P3HT)/AIMs solar cells were fabricated and the effect of the AIM alkyl chain length and the P3HT:AIM ratio on the solar cell performance was studied. The power conversion efficiencies of about 2% were measured in the P3HT/AIM devices with 1:0.4 P3HT:AIM weight ratio for the AIMs with hexadecyl and dodecyl substituents. From the optical and AFM data, we suggested that the AIMs, in contrast to [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), do not disturb the P3HT crystalline domains. Moreover, the more soluble AIMs do not show a better miscibility with the P3HT crystalline phase.

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Double-Excitation Dynamics in m-LPPP probed with sub-20 fs Time Resolution

MRS Proceedings ◽

10.1557/proc-771-l5.6 ◽

2003 ◽

Vol 771 ◽

Author(s):

C. Gadermaier ◽

G. Cerullo ◽

C. Manzoni ◽

U. Scherf ◽

E.J.W. List ◽

...

Keyword(s):

Vibrational Relaxation ◽

Broad Band ◽

Generation Efficiency ◽

Exciton Dissociation ◽

Charge Generation ◽

Carrier Generation ◽

Dissociation Probability ◽

Ultrafast Relaxation ◽

First Excited State ◽

Differential Transmission

AbstractIn a novel modification of transient differential transmission spectroscopy, the first excited state S1 is reexcited via a second laser pulse towards a higher lying state Sn. The dynamics of the relaxation of this state Sn as well as the states created from Sn are revealed by a broad-band probe pulse.We find that the charge carrier generation efficiency from Sn is higher compared to S1. The push and probe durations below 20 fs enable the temporal resolution of the ultrafast relaxation of the Sn state and enables us to identify the two main contributions to enhanced charge generation from Sn, energy migration towards sites of high dissociation probability, and exciton dissociation during vibrational relaxation.

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Effect of the double grading on the internal electric field and on the carrier collection in CIGS solar cells

Solar Energy Materials and Solar Cells ◽

10.1016/j.solmat.2020.110948 ◽

2021 ◽

Vol 223 ◽

pp. 110948

Author(s):

Alban Lafuente-Sampietro ◽

Katsuhisa Yoshida ◽

Shenghao Wang ◽

Shogo Ishizuka ◽

Hajime Shibata ◽

...

Keyword(s):

Solar Cells ◽

Electric Field ◽

Internal Electric Field ◽

Carrier Collection ◽

Cigs Solar Cells

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Optimization of Sb2S3 Nanocrystal Concentrations in P3HT: PCBM Layers to Improve the Performance of Polymer Solar Cells

Polymers ◽

10.3390/polym13132152 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2152

Author(s):

E. M. Mkawi ◽

Y. Al-Hadeethi ◽

R. S. Bazuhair ◽

A. S. Yousef ◽

E. Shalaan ◽

...

Keyword(s):

Solar Cells ◽

Doping Concentration ◽

Polymer Solar Cells ◽

Energy Levels ◽

Acid Methyl Ester ◽

Visible Absorption ◽

Block Polymer ◽

Coating Method ◽

Electronic Parameters ◽

P Type

In this study, polymer solar cells were synthesized by adding Sb2S3 nanocrystals (NCs) to thin blended films with polymer poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) as the p-type material prepared via the spin-coating method. The purpose of this study is to investigate the dependence of polymer solar cells’ performance on the concentration of Sb2S3 nanocrystals. The effect of the Sb2S3 nanocrystal concentrations (0.01, 0.02, 0.03, and 0.04 mg/mL) in the polymer’s active layer was determined using different characterization techniques. X-ray diffraction (XRD) displayed doped ratio dependences of P3HT crystallite orientations of P3HT crystallites inside a block polymer film. Introducing Sb2S3 NCs increased the light harvesting and regulated the energy levels, improving the electronic parameters. Considerable photoluminescence quenching was observed due to additional excited electron pathways through the Sb2S3 NCs. A UV–visible absorption spectra measurement showed the relationship between the optoelectronic properties and improved surface morphology, and this enhancement was detected by a red shift in the absorption spectrum. The absorber layer’s doping concentration played a definitive role in improving the device’s performance. Using a 0.04 mg/mL doping concentration, a solar cell device with a glass /ITO/PEDOT:PSS/P3HT-PCBM: Sb2S3:NC/MoO3/Ag structure achieved a maximum power conversion efficiency of 2.72%. These Sb2S3 NCs obtained by solvothermal fabrication blended with a P3HT: PCBM polymer, would pave the way for a more effective design of organic photovoltaic devices.

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