scholarly journals Are hot charge transfer states the primary cause of efficient free-charge generation in polymer:fullerene organic photovoltaic devices? A kinetic Monte Carlo study

2014 ◽  
Vol 16 (38) ◽  
pp. 20310-20320 ◽  
Author(s):  
Matthew L. Jones ◽  
Reesha Dyer ◽  
Nigel Clarke ◽  
Chris Groves
Keyword(s):  
Monte Carlo ◽  
Charge Transfer ◽  
Kinetic Monte Carlo ◽  
Monte Carlo Study ◽  
Organic Photovoltaic ◽  
Free Charge ◽  
Photovoltaic Devices ◽  
Organic Photovoltaic Devices ◽  
Charge Generation

scholarly journals Free Charge Photogeneration in a Single Component High Photovoltaic Efficiency Organic Semiconductor

2021 ◽  
Author(s):  
Justin Hodgkiss ◽  
Michael Price ◽  
Paul Hume ◽  
Aleksandra Ilina ◽  
Isabella Wagner ◽  
...  
Keyword(s):  
Organic Semiconductors ◽  
Organic Photovoltaics ◽  
Photovoltaic Cells ◽  
Single Component ◽  
Dielectric Constants ◽  
Organic Photovoltaic ◽  
Free Charge ◽  
Photovoltaic Devices ◽  
Organic Photovoltaic Devices ◽  
Charge Generation

Abstract Organic photovoltaic cells promise cheap, flexible and scalable solar energy. Whereas light directly generates free charges in silicon photovoltaic cells, bound electron and hole pairs known as excitons are understood to be the primary excitations in organic semiconductors due to their low dielectric constants. These excitons must then be split apart at molecular heterojunctions in order to extract current. Recent record efficiency organic photovoltaics utilise the small molecule, Y6, as a key component in the photon-absorbing blend layer. This molecule and its analogues – unlike previous organic semiconductors – have both low band-gaps and high dielectric constants. Here we show that, in a neat film of Y6, these factors lead to intrinsic free charge generation without the need for a molecular heterojunction to split the exciton. We use a suite of intensity-dependent optical spectroscopy measurements to show that a significant (20-90%) fraction of free charges exist in equilibrium with bound states at light intensity equivalent to 1 sun. Rapid bimolecular charge recombination constrains single component Y6 organic photovoltaic devices to low efficiencies, but this recombination is reduced by the introduction of small quantities of donor polymer. Quantum-chemical calculations reveal charge generation pathways through strong coupling between exciton and CT states, and an intermolecular polarisation pattern that drives exciton dissociation. Our results challenge the understanding of how current record efficiency organic photovoltaics operate, and point towards new future possibilities – offering a molecular picture of intrinsic charge generation as a platform to improve charge yields, and renewing the possibility of efficient single-component organic photovoltaic devices.

Quantum efficiency of exciton-to-charge generation in organic photovoltaic devices

2001 ◽  
Vol 89 (10) ◽  
pp. 5564-5569 ◽  
Author(s):  
Leif A. A. Pettersson ◽  
Lucimara S. Roman ◽  
Olle Inganäs
Keyword(s):  
Quantum Efficiency ◽  
Organic Photovoltaic ◽  
Photovoltaic Devices ◽  
Organic Photovoltaic Devices ◽  
Charge Generation

scholarly journals Charge-Transfer State Dynamics Following Hole and Electron Transfer in Organic Photovoltaic Devices

2012 ◽  
Vol 4 (1) ◽  
pp. 209-215 ◽  
Author(s):  
Artem A. Bakulin ◽  
Stoichko D. Dimitrov ◽  
Akshay Rao ◽  
Philip C. Y. Chow ◽  
Christian B. Nielsen ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Charge Transfer State ◽  
Organic Photovoltaic ◽  
Photovoltaic Devices ◽  
Organic Photovoltaic Devices ◽  
Transfer State

scholarly journals Open-Circuit Voltage Losses in Selenium-Substituted Organic Photovoltaic Devices from Increased Density of Charge-Transfer States

2015 ◽  
Vol 27 (19) ◽  
pp. 6583-6591 ◽  
Author(s):  
Dana B. Sulas ◽  
Kai Yao ◽  
Jeremy J. Intemann ◽  
Spencer T. Williams ◽  
Chang-Zhi Li ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Organic Photovoltaic ◽  
Photovoltaic Devices ◽  
Organic Photovoltaic Devices

Effects of the charge-transfer reorganization energy on the open-circuit voltage in small-molecular bilayer organic photovoltaic devices: comparison of the influence of deposition rates of the donor

2016 ◽  
Vol 18 (18) ◽  
pp. 12651-12661 ◽  
Author(s):  
Chih-Chien Lee ◽  
Wei-Cheng Su ◽  
Wen-Chang Chang
Keyword(s):  
Charge Transfer ◽  
Deposition Rate ◽  
Open Circuit Voltage ◽  
Reorganization Energy ◽  
Open Circuit ◽  
Organic Photovoltaic ◽  
Photovoltaic Devices ◽  
Organic Photovoltaic Devices ◽  
Deposition Rates

The reorganization, which determines the open-circuit voltage of organic photovoltaic devices, is highly dependent on the deposition rate of TAPC.

Sign in / Sign up

Export Citation Format

Share Document