Systematic study of exciton diffusion length in organic semiconductors by six experimental methods

2014 ◽  
Vol 1 (2) ◽  
pp. 280-285 ◽  
Author(s):  
Jason D. A. Lin ◽  
Oleksandr V. Mikhnenko ◽  
Jingrun Chen ◽  
Zarifi Masri ◽  
Arvydas Ruseckas ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Systematic Study ◽  
Diffusion Length ◽  
Experimental Methods ◽  
Chemical Modifications ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

Six techniques are used to measure the exciton diffusion length as a function of systematic chemical modifications.

scholarly journals Long-range exciton diffusion in molecular non-fullerene acceptors

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuliar Firdaus ◽  
Vincent M. Le Corre ◽  
Safakath Karuthedath ◽  
Wenlan Liu ◽  
Anastasia Markina ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Diffusion Length ◽  
Crystal Packing ◽  
Maximum Size ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Donor And Acceptor ◽  
Wide Range ◽  
20 Nm ◽  
End Group

Abstract The short exciton diffusion length associated with most classical organic semiconductors used in organic photovoltaics (5-20 nm) imposes severe limits on the maximum size of the donor and acceptor domains within the photoactive layer of the cell. Identifying materials that are able to transport excitons over longer distances can help advancing our understanding and lead to solar cells with higher efficiency. Here, we measure the exciton diffusion length in a wide range of nonfullerene acceptor molecules using two different experimental techniques based on photocurrent and ultrafast spectroscopy measurements. The acceptors exhibit balanced ambipolar charge transport and surprisingly long exciton diffusion lengths in the range of 20 to 47 nm. With the aid of quantum-chemical calculations, we are able to rationalize the exciton dynamics and draw basic chemical design rules, particularly on the importance of the end-group substituent on the crystal packing of nonfullerene acceptors.

scholarly journals Direct Measurement of the Triplet Exciton Diffusion Length in Organic Semiconductors

2012 ◽  
Vol 108 (13) ◽  
Author(s):  
Oleksandr V. Mikhnenko ◽  
Roald Ruiter ◽  
Paul W. M. Blom ◽  
Maria Antonietta Loi
Keyword(s):  
Organic Semiconductors ◽  
Direct Measurement ◽  
Diffusion Length ◽  
Triplet Exciton ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

Role of impurities in determining the exciton diffusion length in organic semiconductors

2016 ◽  
Vol 108 (16) ◽  
pp. 163301 ◽  
Author(s):  
Ian J. Curtin ◽  
D. Wayne Blaylock ◽  
Russell J. Holmes
Keyword(s):  
Organic Semiconductors ◽  
Diffusion Length ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

Evaluating the role of energetic disorder and thermal activation in exciton transport

2016 ◽  
Vol 4 (16) ◽  
pp. 3437-3442 ◽  
Author(s):  
S. Matthew Menke ◽  
Russell J. Holmes
Keyword(s):  
Organic Semiconductors ◽  
Thermal Activation ◽  
Diffusion Length ◽  
Temperature Dependent ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Exciton Transport ◽  
Energetic Disorder ◽  
Boron Subphthalocyanine

Temperature dependent measurements of the exciton diffusion length (LD) are performed for three archetypical small-molecule, organic semiconductors: aluminum tris-(8-hydroxyquinoline) (Alq3), dicyanovinyl-terthiophene (DCV3T), and boron subphthalocyanine chloride (SubPc).

scholarly journals Relationship between Crystalline Order and Exciton Diffusion Length in Molecular Organic Semiconductors

2010 ◽  
Vol 22 (11) ◽  
pp. 1233-1236 ◽  
Author(s):  
Richard R. Lunt ◽  
Jay B. Benziger ◽  
Stephen R. Forrest
Keyword(s):  
Organic Semiconductors ◽  
Diffusion Length ◽  
Crystalline Order ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length

Measurement of the triplet exciton diffusion length in organic semiconductors

2019 ◽  
Vol 7 (19) ◽  
pp. 5695-5701 ◽  
Author(s):  
Deepesh Rai ◽  
Russell J. Holmes
Keyword(s):  
Thin Films ◽  
Organic Semiconductors ◽  
Organic Semiconductor ◽  
Diffusion Length ◽  
Triplet Exciton ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Semiconductor Thin Films ◽  
Quenching Efficiency ◽  
Triplet Excitons

We develop a methodology to measure the diffusion of dark triplet excitons in organic semiconductor thin films using a phosphorescent sensitizer-based approach that explicitly quantifies quenching efficiency by varying sensitizer concentration.

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.

Vertically Optimized Phase Separation with Improved Exciton Diffusion Enables High-Efficiency Organic Solar Cells with Thick Active Layers

2021 ◽  
Author(s):  
Yanming Sun ◽  
Yunhao Cai ◽  
Qian Li ◽  
Guanyu Lu ◽  
Hwa Sook Ryu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Phase Separation ◽  
Active Layer ◽  
Organic Solar Cells ◽  
High Efficiency ◽  
Diffusion Length ◽  
Active Layer Thickness ◽  
Exciton Diffusion ◽  
Exciton Diffusion Length ◽  
Active Layers

Abstract The development of high-performance organic solar cells (OSCs) with thick active layers is of crucial importance for the roll-to-roll printing of large-area solar panels. Unfortunately, increasing the active layer thickness usually results in a significant reduction in efficiency. Herein, we fabricated efficient thick-film OSCs with an active layer consisting of one polymer donor and two non-fullerene acceptors. The two acceptors were found to possess enlarged exciton diffusion length in the mixed phase, which is beneficial to exciton generation and dissociation. Additionally, layer by layer approach was employed to optimize the vertical phase separation. Benefiting from the synergetic effects of enlarged exciton diffusion length and graded vertical phase separation, a record high efficiency of 17.31% (certified value of 16.9%) was obtained for the 300 nm-thick OSC, with an unprecedented short-circuit current density of 28.36 mA cm−2, and a high fill factor of 73.0%. Moreover, the device with an active layer thickness of 500 nm also shows a record efficiency of 15.21%. This work provides new insights into the fabrication of high-efficiency OSCs with thick active layers.

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