Abstract
A novel class of organic semiconductors aimed at improving the efficiency of organic photovoltaic devices is investigated by an ab initio electronic structure theory. Two conjugated block copolymers composed of chemically bound donor and acceptor blocks show substantial charge transfer upon photoexcitation, suggesting that the optically excited states are separated charge pairs rather than strongly interacting charges forming excitons. In contrast, little charge transfer is seen in the ground electronic state. The optical cross-sections of the charge separated states are quite high due to a good overlap of the tails of the ground and excited state wavefunctions. The absorption spectra of the systems cover visible spectrum and extend to the infrared, suggesting good prospects for light harvesting. The calculation results indicate that the proposed class of semiconducting molecular heterojunctions may overcome the exciton bottleneck problem in organic photovoltaic materials.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.