MENU ▼
Read by QxMD icon Read
search
OPEN IN READ APP
JOURNAL ARTICLE

Determining exciton coherence from the photoluminescence spectral line shape in poly(3-hexylthiophene) thin films

Frank C Spano, Jenny Clark, Carlos Silva, Richard H Friend
Journal of Chemical Physics 2009 February 21, 130 (7): 074904
19239313
The photoluminescence (PL) spectral line shape of regioregular poly(3-hexylthiophene) thin films is analyzed using a model which treats the polymer pi-stacks as H-aggregates with exciton-vibrational coupling and spatially correlated site disorder. The Stokes shift, linewidth, and relative vibronic peak intensities in the low-temperature PL spectrum (T=10 K) are accurately reproduced, allowing the coherence function corresponding to the lowest energy (emitting) exciton to be determined from the ratio of the 0-0 to 0-1 peak intensities. The exciton migration length is determined from the N-dependent Stokes shift, where N is the number of segments comprising the stack. Based on the temperature dependence of the PL spectrum it is concluded that emission arises from a low concentration of aggregates which are more disordered than the dominant species responsible for absorption. The emissive aggregates are characterized by shorter average conjugation lengths and hence greater exciton bandwidths. The coherence length of the emitting exciton is estimated to be only three lattice spacings ( approximately 1.1 nm) along the pi-stacking direction. By contrast, the exciton migration length for incoherent hopping between coherent domains is estimated to be approximately 15 nm.

Comments

You need to log in or sign up for an account to be able to comment.

No comments yet, be the first to post one!

Related Papers

Available on the App Store

Available on the Play Store
Remove bar
Read by QxMD icon Read
19239313
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"