Magnetic field effects on singlet fission dynamics

Influence of Excited-State Delocalization on Singlet Fission: Tuning Triplet-Pair-State Emission in Thin Films

“…Instead, to explain the red-shift and the decrease in decay rates, another excited-state species is needed, most likely the 1 (TT) state, which is visible in luminescence via Herzberg–Teller coupling . The triplet-pair state is expected to have a long lifetime for a variety of singlet fission materials ,,, and, in the case of ADT, is expected to be visible by emission at an energy of h ν TT = 2 E ( T 1 ) − normalℏ ω vib ≈ 2 × 1.05 .25em eV − 0.17 .25em eV = 1.93 .25em eV The energy value is calculated by taking twice the triplet energy minus the energy of the vibrational mode related to the vibronic progression of the 1 (TT) state luminescence (0.17 eV), which is needed for Herzberg–Teller coupling. Note that 1 (TT) luminescence has been found previously in an ADT derivative at 1.99 eV .…”

Robust singlet fission process in strong absorption π-expanded diketopyrrolopyrroles

“…As a multiexciton generation pathway, singlet ssion (SF) has drawn more and more attention on account of its great potential that could mitigate the thermal loss and boost the efficiency of solar cells. [1][2][3][4][5][6] Although an SF-active solar cell with an external quantum efficiency above 100% has already been fabricated successfully, 2 the practical power conversion efficiency of the corresponding solar cells are far behind those of conventional devices. 3,4 The primary reason might lie in the limited scope of SF materials, which remain fairly centralized in acene and its derivatives.…”

“…3,4 The primary reason might lie in the limited scope of SF materials, which remain fairly centralized in acene and its derivatives. [3][4][5][6][7][8] These polycyclic compounds, exemplied by tetracene and pentacene, suffer from poor chemical stability upon exposure to air and the trade-off between SF properties and energetics. 3 For practical light harvesting applications, besides the energetic requirement that the energy of its singlet state needs to be close to two times that of its triplet state, i.e.…”

“…11,12 Therefore, designing and developing new SF-capable compounds aiming at practical application remains an urgent but challenging task. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Diketopyrrolopyrroles (DPPs) represent a series of promising organic semiconductors in optoelectronic applications, i.e. organic solar cells and organic eld effect transistors.…”

“…11,12 Therefore, designing and developing new SF-capable compounds aiming at practical application remains an urgent but challenging task. 3–19…”