Optical properties of low band gap alternating copolyfluorenes for photovoltaic devices
(2005) In Journal of Chemical Physics 123(20). p.9-204718- Abstract
- In a joint experimental and theoretical work the optical response and excited-state character of two novel conjugated polymers for photovoltaic applications are studied. The polymers, alternating polyfluorene (APFO) Green 1 and APFO Green 2, are both copolymers of fluorene, thiophene, and electron accepting groups. The band gaps are extended into the red and near infrared with onsets of 780 and 1000 nm, respectively, due to alternating donor and acceptor moieties along the polymer chain. Spectroscopic ellipsometry and subsequent modeling made it possible to extract the dielectric function in the range of 260–1200 nm. Semiempirical quantum chemical calculations (ZINDO) revealed the character of the main electronic transitions in the studied... (More)
- In a joint experimental and theoretical work the optical response and excited-state character of two novel conjugated polymers for photovoltaic applications are studied. The polymers, alternating polyfluorene (APFO) Green 1 and APFO Green 2, are both copolymers of fluorene, thiophene, and electron accepting groups. The band gaps are extended into the red and near infrared with onsets of 780 and 1000 nm, respectively, due to alternating donor and acceptor moieties along the polymer chain. Spectroscopic ellipsometry and subsequent modeling made it possible to extract the dielectric function in the range of 260–1200 nm. Semiempirical quantum chemical calculations (ZINDO) revealed the character of the main electronic transitions in the studied spectral region. The spectral band just above 400 nm was assigned to a delocalized –* transition for both polymers. The red band lying at 622 and 767 nm in the two polymers corresponds to an electronic state mainly occupying the acceptor units and having a strong charge-transfer character. We show that the ZINDO transition energies are valuable input to the application of Lorentz oscillators in modeling of the dielectric function of the polymer material. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/157823
- author
- Persson, N-K ; Sun, Mengtao LU ; Kjellberg, Pär LU ; Pullerits, Tönu LU and Inganas, O
- organization
- publishing date
- 2005
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Chemical Physics
- volume
- 123
- issue
- 20
- pages
- 9 - 204718
- publisher
- American Institute of Physics (AIP)
- external identifiers
-
- wos:000233661000073
- scopus:28344433852
- ISSN
- 0021-9606
- DOI
- 10.1063/1.2087367
- language
- English
- LU publication?
- yes
- additional info
- The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Chemical Physics (S) (011001060)
- id
- 96b59a3c-ef63-4987-8a93-b0a5b6a8ad80 (old id 157823)
- date added to LUP
- 2016-04-01 11:58:32
- date last changed
- 2022-03-28 18:23:08
@article{96b59a3c-ef63-4987-8a93-b0a5b6a8ad80,
abstract = {{In a joint experimental and theoretical work the optical response and excited-state character of two novel conjugated polymers for photovoltaic applications are studied. The polymers, alternating polyfluorene (APFO) Green 1 and APFO Green 2, are both copolymers of fluorene, thiophene, and electron accepting groups. The band gaps are extended into the red and near infrared with onsets of 780 and 1000 nm, respectively, due to alternating donor and acceptor moieties along the polymer chain. Spectroscopic ellipsometry and subsequent modeling made it possible to extract the dielectric function in the range of 260–1200 nm. Semiempirical quantum chemical calculations (ZINDO) revealed the character of the main electronic transitions in the studied spectral region. The spectral band just above 400 nm was assigned to a delocalized –* transition for both polymers. The red band lying at 622 and 767 nm in the two polymers corresponds to an electronic state mainly occupying the acceptor units and having a strong charge-transfer character. We show that the ZINDO transition energies are valuable input to the application of Lorentz oscillators in modeling of the dielectric function of the polymer material.}},
author = {{Persson, N-K and Sun, Mengtao and Kjellberg, Pär and Pullerits, Tönu and Inganas, O}},
issn = {{0021-9606}},
language = {{eng}},
number = {{20}},
pages = {{9--204718}},
publisher = {{American Institute of Physics (AIP)}},
series = {{Journal of Chemical Physics}},
title = {{Optical properties of low band gap alternating copolyfluorenes for photovoltaic devices}},
url = {{http://dx.doi.org/10.1063/1.2087367}},
doi = {{10.1063/1.2087367}},
volume = {{123}},
year = {{2005}},
}