Efficient Charge Generation via Hole Transfer in Dilute Organic Donor–Fullerene Blends

2020 ◽  
Vol 11 (6) ◽  
pp. 2203-2210 ◽  
Author(s):  
Yin Song ◽  
Alexander Schubert ◽  
Xiao Liu ◽  
Srijana Bhandari ◽  
Stephen R. Forrest ◽  
...  
2019 ◽  
Author(s):  
Yin Song ◽  
Alexander Schubert ◽  
Xiao Liu ◽  
Srijana Bhandari ◽  
Stephen R. Forrest ◽  
...  

<p>Efficient organic photovoltaics (OPVs) require broadband charge photogeneration with near-unity quantum yield. This can only be achieved by exploiting all pathways that generate charge. Electron transfer from organic donors to acceptors has been well-studied and is considered the primary path to charge photogeneration in OPVs. In contrast, much less is known about the hole transfer pathway. </p><p>Here we study charge photogeneration in an archetypical system comprising tetraphenyldibenzoperiflanthene: C70 blends using our recently developed multispectral two dimensional electronic spectroscopy (M-2DES), supported by time-dependent density functional theory and fully quantum-mechanical Fermi’s golden rule rate calculations. Our approach identifies in real time two rapid charge transfer pathways that are confirmed through computational analysis. Surprisingly, we find that both electron and hole transfer occur with comparable rates and efficiencies, facilitated by donor-acceptor electronic interactions. Our results highlight the importance of the hole transfer pathway for optimizing the efficiency of OPV devices employing small-molecule heterojunctions.<br></p>


2019 ◽  
Author(s):  
Yin Song ◽  
Alexander Schubert ◽  
Xiao Liu ◽  
Srijana Bhandari ◽  
Stephen R. Forrest ◽  
...  

<p>Efficient organic photovoltaics (OPVs) require broadband charge photogeneration with near-unity quantum yield. This can only be achieved by exploiting all pathways that generate charge. Electron transfer from organic donors to acceptors has been well-studied and is considered the primary path to charge photogeneration in OPVs. In contrast, much less is known about the hole transfer pathway. </p><p>Here we study charge photogeneration in an archetypical system comprising tetraphenyldibenzoperiflanthene: C70 blends using our recently developed multispectral two dimensional electronic spectroscopy (M-2DES), supported by time-dependent density functional theory and fully quantum-mechanical Fermi’s golden rule rate calculations. Our approach identifies in real time two rapid charge transfer pathways that are confirmed through computational analysis. Surprisingly, we find that both electron and hole transfer occur with comparable rates and efficiencies, facilitated by donor-acceptor electronic interactions. Our results highlight the importance of the hole transfer pathway for optimizing the efficiency of OPV devices employing small-molecule heterojunctions.<br></p>


Author(s):  
Mengyun Jiang ◽  
Hairui Bai ◽  
Hongfu Zhi ◽  
Lu Yan ◽  
Han Young Woo ◽  
...  

How to manipulate the phase separation and molecular arrangement to meet the need of efficient charge generation and extraction remains as the long-standing challenge in all-small-molecule organic solar cells (ASM-OSCs)....


Author(s):  
L. Benatto ◽  
C. A. M. Moraes ◽  
G. Candiotto ◽  
K. R. A. Sousa ◽  
J. P. A. Souza ◽  
...  

Our results provide a simple relationship involving the driving force and binding energy of CT state to maximize charge generation in non-fullerene organic solar cells.


2019 ◽  
Vol 99 (2) ◽  
Author(s):  
Friedrich Roth ◽  
Stefan Neppl ◽  
Andrey Shavorskiy ◽  
Tiberiu Arion ◽  
Johannes Mahl ◽  
...  

2020 ◽  
Vol 6 (7) ◽  
pp. eaay5225 ◽  
Author(s):  
Basudev Pradhan ◽  
Sonali Das ◽  
Jinxin Li ◽  
Farzana Chowdhury ◽  
Jayesh Cherusseri ◽  
...  

Organic-inorganic halide perovskite quantum dots (PQDs) constitute an attractive class of materials for many optoelectronic applications. However, their charge transport properties are inferior to materials like graphene. On the other hand, the charge generation efficiency of graphene is too low to be used in many optoelectronic applications. Here, we demonstrate the development of ultrathin phototransistors and photonic synapses using a graphene-PQD (G-PQD) superstructure prepared by growing PQDs directly from a graphene lattice. We show that the G-PQDs superstructure synchronizes efficient charge generation and transport on a single platform. G-PQD phototransistors exhibit excellent responsivity of 1.4 × 108 AW–1 and specific detectivity of 4.72 × 1015 Jones at 430 nm. Moreover, the light-assisted memory effect of these superstructures enables photonic synaptic behavior, where neuromorphic computing is demonstrated by facial recognition with the assistance of machine learning. We anticipate that the G-PQD superstructures will bolster new directions in the development of highly efficient optoelectronic devices.


2012 ◽  
Vol 24 (8) ◽  
pp. 1055-1061 ◽  
Author(s):  
Ajay K. Pandey ◽  
Muhsen Aljada ◽  
Marappan Velusamy ◽  
Paul L. Burn ◽  
Paul Meredith

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