Bipolaron Formation in Organic Solar Cells Observed by Pulsed Electrically Detected Magnetic Resonance

TY - JOUR

T1 - Bipolaron Formation in Organic Solar Cells Observed by Pulsed Electrically Detected Magnetic Resonance

A1 - Behrends,J.

A1 - Schnegg,A.

A1 - Lips,K.

A1 - Thomsen,E. A.

A1 - Pandey,A. K.

A1 - Samuel,I. D. W.

A1 - Keeble,D. J.

AU - Behrends,J.

AU - Schnegg,A.

AU - Lips,K.

AU - Thomsen,E. A.

AU - Pandey,A. K.

AU - Samuel,I. D. W.

AU - Keeble,D. J.

PY - 2010/10/19

Y1 - 2010/10/19

N2 - <p>We report the observation of a spin-dependent dark transport current, exhibiting spin coherence at room temperature, in a pi-conjugated polymer-fullerene blend using pulsed electrically detected magnetic resonance. The resonance at g = 2.0028(3) is due to polarons in the polymer, and exhibits spin locking at high microwave fields. The presence of an excess of fullerene, and the operating voltage (1 V) used, suppresses negative polaron formation in the polymer. It is concluded that spin-dependent transport is due to the formation of positive bipolarons.</p>

AB - <p>We report the observation of a spin-dependent dark transport current, exhibiting spin coherence at room temperature, in a pi-conjugated polymer-fullerene blend using pulsed electrically detected magnetic resonance. The resonance at g = 2.0028(3) is due to polarons in the polymer, and exhibits spin locking at high microwave fields. The presence of an excess of fullerene, and the operating voltage (1 V) used, suppresses negative polaron formation in the polymer. It is concluded that spin-dependent transport is due to the formation of positive bipolarons.</p>

KW - RADICAL PAIRS

KW - MEH-PPV

KW - SEMICONDUCTORS

KW - POLYMER

KW - MAGNETORESISTANCE

KW - EXCITONS

KW - EPR

U2 - 10.1103/PhysRevLett.105.176601

DO - 10.1103/PhysRevLett.105.176601

M1 - Article

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 17

VL - 105

SP - -

ER -