Optical and magnetic probes of hot singlet exciton fission in pi-conjugated polymers for organic photovoltaic applications

Yaxin Zhai; Ella Olejnik; Z. Valy Vardeny

doi:10.1117/12.2187596

5 September 2015 Optical and magnetic probes of hot singlet exciton fission in π-conjugated polymers for organic photovoltaic applications

Yaxin Zhai, Ella Olejnik, Z. Valy Vardeny

Author Affiliations +

Proceedings Volume 9564, Light Manipulating Organic Materials and Devices II; 95640A (2015) https://doi.org/10.1117/12.2187596
Event: SPIE Organic Photonics + Electronics, 2015, San Diego, California, United States

Abstract

We used steady state and picosecond transient photoinduced absorption (PA), excitation dependence (EXPA(ω)) spectrum of the triplet exciton PA band, and its magneto-PA (MPA(B)) response to investigate singlet fission (SF) of hot-excitons into two separated triplet excitons in luminescent π-conjugated polymers. From the high energy step in the triplet EXPA(ω) spectrum of poly(dioctyloxy)-phenylenevinylene (DOO-PPV) films, we identified a hot-exciton SF (HE-SF) process having threshold energy at E≈2ET (=2.8 eV, where E_T is the energy of the lowest lying triplet exciton), which is about 0.8 eV above the lowest singlet exciton energy. The picosecond transient PA with 3.1 eV pump excitation shows that in DOO-PPV film a triplet exciton is generated at time, t<500 ps. However the ultrafast triplet generation is missing in DOO-PPV solution, indicating that the HE-SF is predominantly interchain in nature. The HE-SF process was confirmed by the triplet MPA(B) response for excitation at E>2E_T, which shows a typical SF response. Our work shows that the SF process in π-conjugated polymers is a much more general process than thought previously.

Conference Presentation

Citation Download Citation

Yaxin Zhai, Ella Olejnik, and Z. Valy Vardeny "Optical and magnetic probes of hot singlet exciton fission in π-conjugated polymers for organic photovoltaic applications", Proc. SPIE 9564, Light Manipulating Organic Materials and Devices II, 95640A (5 September 2015); https://doi.org/10.1117/12.2187596

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available