Platinum–acetylide polymer based solar cells: involvement of the triplet state for energy conversion

Abstract

Relatively efficient photovoltaic devices were fabricated using blends of a phosphorescent platinum-acetylide polymer and a fullerene (PCBM); involvement of the triplet excited state of the platinum-acetylide polymer in photoinduced charge transfer is believed to contribute to the device efficiency.

Polymer‐Fullerene Bulk‐Heterojunction Solar Cells

“…In contrast, metallated conjugated polymers have rarely been tested as donor materials in bulk-heterojunction solar cells. [86,87] In early reports, power-conversion efficiencies significantly below 1% were published. Recently, Wong et al [70] demonstrated highly efficient bulk-heterojunction solar cells using polymer 6 (Fig.…”

Study of intersystem crossing mechanism in organic materials

“…It is known that the spinorbit coupling flips the singlet spin configuration to triplet and vice versa and hence facilitates ISC [6,8,13]. ISC from a singlet excited state to a triplet excited state has been studied theoretically [14][15][16] and as well as experimentally [11,12]. Theoretical models have so far been limited to either numerical calculation of ISC rates [14][15][16] or estimation of the spin-orbit interaction transition matrix element [17].…”

“…The incorporation of iridium (Ir) and platinum (Pt) into the active layer of OSCs results in the phosphorescent sensitizer, fac-tris(2-phenylpyridine) iridium [Ir(ppy)3] [1,10] and platinum-acetylide [p-PtTh] [11] and has been found Intersystem crossing rate from singlet excited state to triplet excited state of an organic molecule has been derived using exciton-spin-orbit-molecular vibration interaction as a perturbation operator. Incorporation of heavy metal atom enhances the spin-orbit interaction and hence the intersystem crossing rate because it depends on the square of the heaviest atomic number.…”

Diffusion Length and Langevin Recombination of Singlet and Triplet Excitons in Organic Heterojunction Solar Cells

“…[8,17] A free e-h pair does not have a distinct singlet or triplet spin character; [14] however, prior to dissociation, a CT exciton will still be spin correlated to the singlet or triplet state. In Equations (12) and (13) we have derived spin-dependent recombination rate constants from which we can calculate how, prior to charge separation of dissociated exciton, the charges can still be drawn back to their original excitonic state and possibly decay to the ground state.…”