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

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

Evolving Trends in Engineering and Technology ◽

10.18052/www.scipress.com/etet.3.30 ◽

2014 ◽

Vol 3 ◽

pp. 30-36

Author(s):

M.R. Merad Boudia ◽

A. Cheknane ◽

B. Benyoucef ◽

A.M. Ferouani ◽

H.S. Hilal

Keyword(s):

Solar Cells ◽

Electric Field ◽

Weight Ratio ◽

Acid Methyl Ester ◽

Photocurrent Density ◽

Physical Parameters ◽

Exciton Dissociation ◽

Mixture Ratio ◽

Dissociation Probability ◽

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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Enhanced Efficiency of PTB7 : PC61BM Organic Solar Cells by Adding a Low Efficient Polymer Donor

International Journal of Photoenergy ◽

10.1155/2017/4501758 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Joana Farinhas ◽

Ricardo Oliveira ◽

Quirina Ferreira ◽

Jorge Morgado ◽

Ana Charas

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Polymer Solar Cells ◽

Power Conversion ◽

Acid Methyl Ester ◽

Ternary Blend ◽

Device Performance ◽

Blend Morphology ◽

Acid Methyl ◽

Blend Polymer

Ternary blend polymer solar cells combining two electron-donor polymers, poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl] (PTB7) and poly[2,5-bis(3-dodecylthiophen-2-yl)thieno[3,2-b]thiophene] (pBTTT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), as electron-acceptor, were fabricated. The power conversion efficiency of the ternary cells was enhanced by 18%, with respect to the reference binary cells, for a blend composition with 25% (wt%) of pBTTT in the polymers content. The optimized device performance was related to the blend morphology, nonrevealing pBTTT aggregates, and improved charge extraction within the device.

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Improved exciton dissociation efficiency by a carbon-quantum-dot doped workfunction modifying layer in polymer solar cells

Current Applied Physics ◽

10.1016/j.cap.2020.10.019 ◽

2021 ◽

Vol 21 ◽

pp. 140-146

Author(s):

Sujung Park ◽

Heunjeong Lee ◽

Seok Won Park ◽

Tae Eun Kim ◽

Sung Heum Park ◽

...

Keyword(s):

Solar Cells ◽

Quantum Dot ◽

Polymer Solar Cells ◽

Exciton Dissociation ◽

Carbon Quantum Dot ◽

Dissociation Efficiency

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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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Carbazole linked phenylquinoline-based fullerene derivatives as acceptors for bulk heterojunction polymer solar cells: effect of interfacial contacts on device performance

Journal of Materials Chemistry A ◽

10.1039/c4ta00013g ◽

2014 ◽

Vol 2 (19) ◽

pp. 6916 ◽

Cited By ~ 19

Author(s):

Pachagounder Sakthivel ◽

Kakaraparthi Kranthiraja ◽

Chinnusamy Saravanan ◽

Kumarasamy Gunasekar ◽

Hong Il Kim ◽

...

Keyword(s):

Solar Cells ◽

Bulk Heterojunction ◽

Polymer Solar Cells ◽

Device Performance ◽

Fullerene Derivatives

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Diffusion-enhanced exciton dissociation in single-material organic solar cells

Physical Chemistry Chemical Physics ◽

10.1039/d1cp03328j ◽

2021 ◽

Vol 23 (37) ◽

pp. 20848-20853

Author(s):

Nong V. Hoang ◽

Vasileios C. Nikolis ◽

Lukasz Baisinger ◽

Koen Vandewal ◽

Maxim S. Pshenichnikov

Keyword(s):

Solar Cells ◽

Organic Solar Cells ◽

Domain Boundary ◽

Exciton Dissociation ◽

Dissociation Efficiency ◽

Single Material

Multiple crossings at the domain boundary with different molecular orientations enhance the exciton dissociation efficiency in single-material organic solar cells.

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