Ultrafast transient absorption spectroscopy investigation of photoinduced dynamics in poly(3-hexylthiophene)-block-oligo(anthracene-9,10-diyl)

Strain, Jacob

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https://hdl.handle.net/2142/97101 Copy

Description

Title

Ultrafast transient absorption spectroscopy investigation of photoinduced dynamics in poly(3-hexylthiophene)-block-oligo(anthracene-9,10-diyl)

Author(s)

Strain, Jacob

Contributor(s)

• Liu, Jinjun
• Rathnayake, Hemali

Issue Date

2017-06-21

Keyword(s)

Multiple potential energy surfaces

Abstract

Semiconducting polymer nanostructures featuring bulk heterojunction (BHJ) architecture are promising light harvesters in photovoltaic (PV) devices because they allow control of individual domain sizes, internal structure and ordering, as well as well-defined contact between the electron donor and acceptor. Power conversion efficiency (PCE) of PV devices strongly depends on photoinduced dynamics. Understanding and optimizing photoinduced charge transfer processes in BHJ’s hence help improve the performance of PV devices and increase their PCE in particular. We have investigated the photoinduced dynamics of a block polymer containing moieties of poly-3-hexylthiophene (P3HT) and polyanthracene (PANT) in solution and in solid state with femtosecond transient absorption (TA) spectroscopy. The dynamics of the polymer PANT alone are also studied as a control. The TA spectra of PANT includes a strong excited state absorption centered at 610 (nm) along with a stimulated emission signal stretching past the detection limit into the UV region which is absent in the monomer’s spectra in the detection window. The block polymer’s TA spectra strongly resembles that of P3HT but a noticeable positive pull on P3HT’s stimulated emission signal residing at 575-620 (nm) is indicative of the excited state absorption of PANT in the adjacent spectral region. The doubling of the lifetime exciton delocalization on the block polymer versus P3HT alone have alluded that the lifetime of P3HT is extended by the covalent addition of PANT. The current spectroscopic investigation represents an interesting example of photoinduced processes in systems with complex energy level structure. Studies of dependence of change generation and separation on composition, dimension, and morphology of the heterojunctions are in process.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/97101

DOI

https://doi.org/10.15278/isms.2017.WB07

Copyright and License Information

Copyright 2017 Jacob Strain

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