Förster Resonance Energy Transfer between Fluorescent Organic Semiconductors: Poly(9,9-dioctylfluorene-alt-benzothiadiazole) and 6,13-Bis(triisopropylsilylethynyl)pentacene

Abstract

In the present study, an investigation of the electronic excitation energy transfer between two p-type fluorescent semiconductors, F8BT [poly­(9,9-dioctylfluorene-alcohol-benzothiadiazole] and TIPS-P [6,13-bis­(triisopropylsilylethynyl)­pentacene], has been carried out in a chloroform solution using steady-state and time-domain fluorescence techniques. The spectral overlap integral between donor (F8BT) emission and acceptor (TIPS-P) absorption is 2.04 × 1015 nm4/(M cm), and the corresponding critical transfer distance is 53.12 Å. In donor decay dynamics, at the lower acceptor concentrations, the observed results deviate from the Förster theory due to the combined effect of diffusion and energy migration. However, it does not exhibit energy migration and distribution for higher acceptor concentrations, and the system follows the Förster model of resonance excitation energy transfer (FRET). The higher value of the donor–acceptor interaction strength than self-interaction (donor–donor interaction) appears to be responsible for this behavior. Further, in acceptor decay, the appearance of the rise time and its decrease with the acceptor concentration confirms FRET from F8BT to TIPS-P.

New Benzotriazole and Benzodithiophene-Based Conjugated Terpolymer Bearing a Fluorescein Derivative as Side-Group: In-Ternal Förster Resonance Energy Transfer to Improve Organic Solar Cells

“…The use of NFAs has brought back into the game wide-bandgap CPs, which do not require such sophisticated or complex structures to produce high PCEs [ 21 , 22 , 23 ]. Another approach may be using the Förster Resonance Energy Transfer (FRET) process between two molecules by long-range dipole–dipole coupling [ 24 , 25 , 26 ]. A large body of literature on CP-based ternary solar cells suggests that FRET improves the PCE of devices by increasing exciton generation in the photoactive material and facilitating exciton migration over long distances [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ].…”