Absorption cross-sections of hole polarons in glassy and β-phase polyfluorene

Absorption induced by electrochemically injected holes is studied in poly-9,9-dioctylfluorene (PFO) films. Injected charges form positive polarons which are delocalised over four fluorene units in the glassy phase and about seven fluorene units in its β-phase. Polaron absorption cross-sections at the 640 nm peak are similar to the published values of chemically reduced oligofluorenes in solution. The absorption cross-section of polaron in the β-phase at 470 nm is about eight times smaller than the stimulated emission cross-section derived from published data. This indicates that β-phase-rich PFO is an attractive candidate for a light-emitting layer in double-heterostructure organic laser diodes.

'A Kind of Logic, A Kind of Dominant Logic': Navigating Colonialism, Honoring Black Mobility, and Thinking on Moving Through

My thesis thinks through the ways Newtonian logics require linear mobility in order to produce narratives of progress. I argue that this linear mobility, and the resulting logics, potentially erases the chaotic and non-linear motions that are required to navigate a colonial landscape. I suggest that these non-linear movements produce important critiques of the seeming stasis of colonial constructs and highlight the ways these logics must appear neutral and scientific in an attempt to conceal the constant and complex adjustments these frameworks require. In order to make room for these complex motions, I develop a quantum intervention. Specifically, I use quantum physics as a metaphor to think through the significance of black life, the double-consciousness ofland, and the intricate motions of sound. In order to put forth this intervention, I look at news coverage of Hurricane Katrina, Du Bois’s characterization of land in Souls of Black Folks, and the aural mobilities of blackness articulated in an academic discussion and interview about post- humanism.