scholarly journals Effect of Side-Chain Variation on Single-Crystalline Structures for Revealing the Structure–Property Relationships of Organic Solar Cells

2020 ◽  
Vol 02 (01) ◽  
pp. 026-032
Author(s):  
Chen Yang ◽  
Liu Yuan ◽  
Ruimin Zhou ◽  
Zhen Wang ◽  
Jianqi Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Single Crystal ◽  
Crystal Structures ◽  
Organic Solar Cells ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Side Chains ◽  
Single Crystal Structures ◽  
Stacking Structure ◽  
Molecular Stacking

The molecular stacking assembly in the active layer plays a significant role in the photovoltaic performance of organic solar cells (OSCs). Here, we report two new small molecular donors with different side chains, FBT-O and FBT-H, and their corresponding fullerene-based OSCs. A slight change in the side chains led to a big difference in the power conversion efficiencies (PCEs). Although the molecular structures of the two donors are similar to each other, PCEs of the devices based on FBT-O were almost three times higher than those of the devices based on FBT-H, with manifold short-circuit current density, fill factor, as well as three orders of magnitude enhancement in the hole mobility. The difference in their single crystal structures was thoroughly investigated, whereby the FBT-O exhibited better planarity leading to appropriate phase separation and domain size. Furthermore, two-dimensional grazing-incidence wide-angle X-ray scattering results of the blend films revealed that the two donors retained a similar stacking structure as compared to the single-crystal structures, thus, establishing a clear relationship between the molecular stacking structure and the device performance.

scholarly journals With PBDB-T as the Donor, the PCE of Non-Fullerene Organic Solar Cells Based on Small Molecule INTIC Increased by 52.4%

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1324 ◽  
Author(s):  
Weifang Zhang ◽  
Zicha Li ◽  
Suling Zhao ◽  
Zheng Xu ◽  
Bo Qiao ◽  
...  
Keyword(s):  
Solar Cells ◽  
Small Molecule ◽  
Organic Solar Cells ◽  
High Performance ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Production Costs ◽  
Higher Carrier Mobility ◽  
Carrier Transportation

At present, most high-performance non-fullerene materials are centered on fused rings. With the increase in the number of fused rings, production costs and production difficulties increase. Compared with other non-fullerenes, small molecule INTIC has the advantages of easy synthesis and strong and wide infrared absorption. According to our previous report, the maximum power conversion efficiency (PCE) of an organic solar cell using PTB7-Th:INTIC as the active layer was 7.27%. In this work, other polymers, PTB7, PBDB-T and PBDB-T-2F, as the donor materials, with INTIC as the acceptor, are selected to fabricate cells with the same structure to optimize their photovoltaic performance. The experimental results show that the optimal PCE of PBDB-T:INTIC based organic solar cells is 11.08%, which, thanks to the open voltage (VOC) increases from 0.80 V to 0.84 V, the short circuit current (JSC) increases from 15.32 mA/cm2 to 19.42 mA/cm2 and the fill factor (FF) increases from 60.08% to 67.89%, then a 52.4% improvement in PCE is the result, compared with the devices based on PTB7-Th:INTIC. This is because the PBDB-T:INTIC system has better carrier dissociation and extraction, carrier transportation and higher carrier mobility.

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

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 450 ◽  
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.

Application of Electrochemical Impedance Spectroscopy in Organic Solar Cells with Vertically Aligned TiO2 Nanorod Arrays as Buffer Layer

2012 ◽  
Vol 512-515 ◽  
pp. 1598-1603
Author(s):  
Yong Chang Zhang ◽  
Xing Jian Jiao ◽  
Chen Zhou ◽  
He Ping Shen ◽  
Feng Hao ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Buffer Layer ◽  
Organic Solar Cells ◽  
Electrochemical Impedance ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Active Layer Thickness ◽  
Nanorod Arrays

Single-crystal TiO2 nanorod film was synthesized directly on FTO substrates with various lengths by changing the hydrothermal growth parameters including growth time and growth temperature. The obtained nanorod arrays were incorporated in organic solar cells as buffer layer instead of PEDOT: PSS. Results showed that devices assembled with TiO2 nanorods film of 200 nm in length exhibited a lower open-circuit voltage but a significantly higher short-circuit current density compared to those of normal FTO/PEDOT: PSS/P3HT: PCBM/Al structure with a comparable active layer thickness. Overall the power conversion efficiency was boosted by two-fold. Electrochemical impedance spectroscopy (EIS) analyses revealed that the improvement in the photovoltaic performance was induced by the inhibited recombination and consequently enhanced electron lifetime.

Influence of polymer side chains on the photovoltaic performance of non-fullerene organic solar cells

2017 ◽  
Vol 5 (4) ◽  
pp. 937-942 ◽  
Author(s):  
Xue Gong ◽  
Guangwu Li ◽  
Shiyu Feng ◽  
Liangliang Wu ◽  
Yahui Liu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Energy Level ◽  
Organic Solar Cells ◽  
Photovoltaic Performance ◽  
Great Influence ◽  
Molecular Packing ◽  
Side Chains ◽  
Blend Morphology

The side chains of polymers had a great influence on their molecular packing, energy level, blend morphology and photovoltaic performance. The PCEs of 7.28% and 1.55% were obtained for alkoxy and alkylthio-substituted polymer based non-fullerene solar cells, respectively.

HYBRID ORGANIC SOLAR CELLS BLENDED WITH CNTs

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.

Asymmetrical squaraines for high-performance small-molecule organic solar cells with a short circuit current of over 12 mA cm−2

2015 ◽  
Vol 51 (28) ◽  
pp. 6133-6136 ◽  
Author(s):  
Yao Chen ◽  
Youqin Zhu ◽  
Daobin Yang ◽  
Qian Luo ◽  
Lin Yang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Small Molecule ◽  
Organic Solar Cells ◽  
High Performance ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Squaric Acid ◽  
Squaraine Dyes

Asymmetrical squaraine dyes with two aryl groups directly linked to the squaric acid core were synthesized, and exhibited excellent photovoltaic performance.

scholarly journals An investigation of the role acceptor side chains play in the processibility and efficiency of organic solar cells fabricated from small molecular donors featuring 3,4-ethylenedioxythiophene cores

RSC Advances ◽  
2018 ◽  
Vol 8 (69) ◽  
pp. 39231-39240
Author(s):  
N. A. Mica ◽  
S. A. J. Almahmoud ◽  
L. Krishnan Jagadamma ◽  
G. Cooke ◽  
I. D. W. Samuel
Keyword(s):  
Solar Cells ◽  
Small Molecule ◽  
Organic Solar Cells ◽  
Chemical Nature ◽  
Photovoltaic Performance ◽  
Side Chain ◽  
Side Chains ◽  
Acceptor Side

The chemical nature of the acceptor side chain plays an important role in the processability and photovoltaic performance of EDOT-based small molecule donors.

Effect of Non-fullerene Acceptors’ Side Chains on the Morphology and Photovoltaic Performance of Organic Solar Cells

2017 ◽  
Vol 9 (39) ◽  
pp. 33906-33912 ◽  
Author(s):  
Cai’e Zhang ◽  
Shiyu Feng ◽  
Yahui Liu ◽  
Ran Hou ◽  
Zhe Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Photovoltaic Performance ◽  
Side Chains

scholarly journals Design of All-Small-Molecule Organic Solar Cells Approaching 14% Efficiency via Isometric Terminal Alkyl Chain Engineering

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2505
Author(s):  
Haiyan Chen ◽  
Hua Tang ◽  
Dingqin Hu ◽  
Yiqun Xiao ◽  
Jiehao Fu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Small Molecule ◽  
Organic Solar Cells ◽  
High Performance ◽  
Alkyl Chain ◽  
Photovoltaic Performance ◽  
Engineering Process ◽  
Transport Channel ◽  
Fine Tune ◽  
Molecular Stacking

Morphology is crucial to determining the photovoltaic performance of organic solar cells (OSCs). However, manipulating morphology involving only small-molecule donors and acceptors is extremely challenging. Herein, a simple terminal alkyl chain engineering process is introduced to fine-tune the morphology towards high-performance all-small-molecule (ASM) OSCs. We successfully chose a chlorinated two-dimension benzo[1,2-b:4,5-b′]dithiophene (BDT) central unit and two isomeric alkyl cyanoacetate as the end-capped moieties to conveniently synthesize two isomeric small-molecule donors, namely, BT-RO-Cl and BT-REH-Cl, each bearing linear n-octyl (O) as the terminal alkyl chain and another branched 2-ethylhexyl (EH) as the terminal alkyl chain. The terminal alkyl chain engineering process provided BT-RO-Cl with 13.35% efficiency and BT-REH-Cl with 13.90% efficiency ASM OSCs, both with Y6 as the electron acceptor. The successful performance resulted from uniform phase separation and the favorable combination of face-on and edge-on molecular stacking of blended small-molecule donors and acceptors, which formed a fluent 3D transport channel and thus delivered high and balanced carrier mobilities. These findings demonstrate that alkyl chain engineering can finely control the morphology of ASM OSCs, and provides an alternative for the optimal design of small-molecule materials towards high-performance ASM OSCs.

scholarly journals Characterising Exciton Generation in Bulk-Heterojunction Organic Solar Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 209
Author(s):  
Kiran Sreedhar Ram ◽  
Hooman Mehdizadeh-Rad ◽  
David Ompong ◽  
Daniel Setsoafia ◽  
Jai Singh
Keyword(s):  
Solar Cells ◽  
Electric Fields ◽  
Active Layer ◽  
Organic Solar Cells ◽  
Bulk Heterojunction ◽  
Short Circuit ◽  
Photovoltaic Performance ◽  
Short Circuit Current ◽  
Photon Absorption ◽  
Active Layer Thickness

In this paper, characterisation of exciton generation is carried out in three bulk-heterojunction organic solar cells (BHJ OSCs)—OSC1: an inverted non-fullerene (NF) BHJ OSC; OSC2: a conventional NF BHJ OSC; and OSC3: a conventional fullerene BHJ OSC. It is found that the overlap of the regions of strong constructive interference of incident and reflected electric fields of electromagnetic waves and those of high photon absorption within the active layer depends on the active layer thickness. An optimal thickness of the active layer can thus be obtained at which this overlap is maximum. We have simulated the rates of total exciton generation and position dependent exciton generation within the active layer as a function of the thicknesses of all the layers in all three OSCs and optimised their structures. Based on our simulated results, the inverted NF BHJ OSC1 is found to have better short circuit current density which may lead to better photovoltaic performance than the other two. It is expected that the results of this paper may provide guidance in fabricating highly efficient and cost effective BHJ OSCs.

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