Effect of CoFe magnetic nanoparticles on the hole transport in poly(2-methoxy, 5-(2-ethylhexiloxy) 1,4-phenylenevinylene)

Abstract

The effect of doping of CoFe magnetic nanoparticles (MNPs) on the hole transport in poly(2-methoxy,5-(2-ethylhexyloxy)-1,4-phenylenevinylene)(MEH-PPV) thin films has been investigated in the temperature range 280–120 K. Hole transport in MEH-PPV is found to be governed by space-charge-limited-conduction (SCLC) with exponential distribution of traps in energy space. Doping of CoFe MNPs in MEH-PPV reduces the hole mobility from 1 × 10−5 to 6 × 10−6 cm2 V−1 s−1 by introducing new trap sites causing their net density increase from 1 × 1018 to 2.1 × 1018 cm−3, which is likely to result in balanced injection and efficient recombination of charge carriers to improve the performance of polymer light emitting diodes.