The Library
A predictive theory of charge separation in organic photovoltaics interfaces
Tools
Tools
Tools
Liu, Tao, Troisi, Alessandro, Caruso, Domenico, Cheung, David L. and McMahon, David P. (2012) A predictive theory of charge separation in organic photovoltaics interfaces. In: Proceedings of SPIE - The International Society for Optical Engineering, San Diego, CA, United States, 14 - 16 Aug 2012. Published in: Proceedings of SPIE - The International Society for Optical Engineering, Volume 8477 Article number 84770Q. doi:10.1117/12.931662 ISSN 0277-786X.
Research output not available from this repository.
Request-a-Copy directly from author or use local Library Get it For Me service.
Official URL: http://dx.doi.org/10.1117/12.931662
Abstract
The key process in organic photovoltaics cells is the separation of an exciton, close to the donor/acceptor interface into a free hole (in the donor) and a free electron (in the acceptor). In an efficient solar cell, the majority of absorbed photons generate such hole-electron pairs but it is not clear why such a charge separation process is so efficient in some blends (for example in the blend formed by poly(3- hexylthiophene) (P3HT) and a C60 derivative (PCBM)) and how can one design better OPV materials. The electronic and geometric structure of the prototypical polymer:fullerene interface (P3HT:PCBM) is investigated theoretically using a combination of classical and quantum simulation methods. It is shown that the electronic structure of P3HT in contact with PCBM is significantly altered compared to bulk P3HT. Due to the additional free volume of the interface, P3HT chains close to PCBM are more disordered and, consequently, they are characterized by an increased band gap. Excitons and holes are therefore repelled by the interface. This provides a possible explanation of the low recombination efficiency and supports the direct formation of “quasi-free” charge separated species at the interface. This idea is further explored here by using a more general system-independent model Hamiltonian. The long range exciton dissociation rate is computed as a function of the exciton distance from the interface and the average dissociation distance is evaluated by comparing this rate with the exciton migration rate with a kinetic model. The phenomenological model shows that also in a generic interface the direct formation if quasi-free charges is extremely likely. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
| Item Type: | Conference Item (Paper) | ||||
|---|---|---|---|---|---|
| Divisions: | Faculty of Science, Engineering and Medicine > Science > Chemistry Faculty of Science, Engineering and Medicine > Science > Centre for Scientific Computing |
||||
| Journal or Publication Title: | Proceedings of SPIE - The International Society for Optical Engineering | ||||
| Publisher: | S P I E - International Society for Optical Engineering | ||||
| ISSN: | 0277-786X | ||||
| Book Title: | Organic Photovoltaics XIII | ||||
| Official Date: | 2012 | ||||
| Dates: |
|
||||
| Volume: | Volume 8477 | ||||
| Page Range: | Article number 84770Q | ||||
| DOI: | 10.1117/12.931662 | ||||
| Status: | Peer Reviewed | ||||
| Publication Status: | Published | ||||
| Access rights to Published version: | Restricted or Subscription Access | ||||
| Conference Paper Type: | Paper | ||||
| Title of Event: | Proceedings of SPIE - The International Society for Optical Engineering | ||||
| Type of Event: | Conference | ||||
| Location of Event: | San Diego, CA, United States | ||||
| Date(s) of Event: | 14 - 16 Aug 2012 |
Request changes or add full text files to a record
Repository staff actions (login required)
 |
View Item |
