Delayed fluorescence material-assisted high performance ternary organic solar cells realized by prolonged exciton lifetime and diffusion length

2020 ◽  
Vol 8 (48) ◽  
pp. 17429-17439
Author(s):  
Luye Cao ◽  
Xiaoyang Du ◽  
Hui Lin ◽  
Caijun Zheng ◽  
Zhenhua Chen ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
High Performance ◽  
Diffusion Length ◽  
Delayed Fluorescence ◽  
Exciton Lifetime ◽  
Fluorescence Material ◽  
And Diffusion

The addition of DF materials into ternary OSCs offers possibilities for prolonging the exciton lifetime and diffusion length.

scholarly journals Small reorganization energy acceptors enable low energy losses in non-fullerene organic solar cells

2021 ◽  
Author(s):  
Yanan Shi ◽  
Yilin Chang ◽  
Kun Lu ◽  
Zhihao Chen ◽  
Jianqi Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Energy Loss ◽  
Organic Solar Cells ◽  
High Performance ◽  
Reorganization Energy ◽  
Photoelectric Conversion ◽  
Exciton Lifetime ◽  
Reorganization Energies ◽  
Vibration Coupling ◽  
The Relationship

Abstract Minimizing the energy loss is of critical importance in the pursuit of attaining high-performance organic solar cells (OSCs). Interestingly, electron-vibration coupling (namely reorganization energy) plays a crucial role in the photo-electric conversion processes. However, a molecular understanding of the relationship between the reorganization energy and the energy loss has rarely been studied. Here, two new acceptors Qx-1 and Qx-2 with quinoxaline (Qx)-containing fused core were designed and synthesized. The results indicate that the reorganization energies of these two acceptors during the photoelectric conversion processes are substantially smaller than the conventional Y6 acceptor, which is beneficial for improving the exciton lifetime and diffusion length, promoting charge transport and reducing the energy loss originating from exciton dissociation and non-radiative recombination. As a result, an outstanding power conversion efficiency (PCE) of 18.2% with high Voc above 0.93 V in the PM6:Qx-2 blend, accompanying a significantly reduced energy loss of 0.48 eV. To the best of our knowledge, the obtained energy loss is the smallest for the binary OSCs with PCEs over 16% reported to date. This work underlines the importance of the reorganization energy in achieving small energy loss in organic active materials and paves a new way to obtain high-performance OSCs.

scholarly journals Pseudo-bilayer architecture enables high-performance organic solar cells with enhanced exciton diffusion length

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kui Jiang ◽  
Jie Zhang ◽  
Zhengxing Peng ◽  
Francis Lin ◽  
Shengfan Wu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Active Layer ◽  
Organic Solar Cells ◽  
High Performance ◽  
Diffusion Length ◽  
Bulk Heterojunction ◽  
Short Circuit ◽  
Full Potential ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

AbstractSolution-processed organic solar cells (OSCs) are a promising candidate for next-generation photovoltaic technologies. However, the short exciton diffusion length of the bulk heterojunction active layer in OSCs strongly hampers the full potential to be realized in these bulk heterojunction OSCs. Herein, we report high-performance OSCs with a pseudo-bilayer architecture, which possesses longer exciton diffusion length benefited from higher film crystallinity. This feature ensures the synergistic advantages of efficient exciton dissociation and charge transport in OSCs with pseudo-bilayer architecture, enabling a higher power conversion efficiency (17.42%) to be achieved compared to those with bulk heterojunction architecture (16.44%) due to higher short-circuit current density and fill factor. A certified efficiency of 16.31% is also achieved for the ternary OSC with a pseudo-bilayer active layer. Our results demonstrate the excellent potential for pseudo-bilayer architecture to be used for future OSC applications.

Determining the exciton diffusion length of copper phthalocyanine in operating planar-heterojunction organic solar cells

2020 ◽  
Vol 89 (3) ◽  
pp. 30201 ◽  
Author(s):  
Xi Guan ◽  
Shiyu Wang ◽  
Wenxing Liu ◽  
Dashan Qin ◽  
Dayan Ban
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Diffusion Length ◽  
Copper Phthalocyanine ◽  
Short Circuit ◽  
Thick Layer ◽  
Short Circuit Current ◽  
Short Circuit Current Density ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

Organic solar cells based on planar copper phthalocyanine (CuPc)/C60 heterojunction have been characterized, in which a 2 nm-thick layer of bathocuproine (BCP) is inserted into the CuPc layer. The thin layer of BCP allows hole current to tunnel it through but blocks the exciton diffusion, thereby altering the steady-state exciton profile in the CuPc zone (zone 1) sandwiched between BCP and C60. The short-circuit current density (JSC) of device is limited by the hole-exciton scattering effect at the BCP/CuPc (zone 1) interface. Based on the variation of JSC with the width of zone 1, the exciton diffusion length of CuPc is deduced to be 12.5–15 nm. The current research provides an easy and helpful method to determine the exciton diffusion lengths of organic electron donors.

High-Performance and Low-Energy Loss Organic Solar Cells with Non-fused Ring Acceptor by Alkyl Chain Engineering

2021 ◽  
pp. 129768
Author(s):  
Dou Luo ◽  
Xue Lai ◽  
Nan Zheng ◽  
Chenghao Duan ◽  
Zhaojin Wang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Energy Loss ◽  
Organic Solar Cells ◽  
High Performance ◽  
Alkyl Chain ◽  
Low Energy ◽  
Fused Ring

A Facile Synthesized Polymer Featuring B‐N Covalent Bond and Small Singlet‐Triplet Gap for High‐Performance Organic Solar Cells

2021 ◽  
Vol 60 (16) ◽  
pp. 8813-8817
Author(s):  
Shuting Pang ◽  
Zhiqiang Wang ◽  
Xiyue Yuan ◽  
Langheng Pan ◽  
Wanyuan Deng ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
High Performance ◽  
Covalent Bond

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.

Alcohol-soluble fluorene derivate functionalized with pyridyl groups as a high-performance cathode interfacial material in organic solar cells

2021 ◽  
Author(s):  
Lin Lin ◽  
Zeping Huang ◽  
Yuanqi Luo ◽  
Tingen Peng ◽  
Baitian He ◽  
...  
Keyword(s):  
Solar Cells ◽  
Organic Photovoltaics ◽  
Organic Solar Cells ◽  
High Performance ◽  
Fluorene Derivative ◽  
Interfacial Material ◽  
Cathode Interlayer

The synthesis and application as a cathode interlayer in organic photovoltaics of a fluorene derivative with pyridyl functional chains are presented.

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