Charge transport in disordered semiconducting polymers driven by nuclear tunneling

The current density-voltage (J-V) characteristics of hole-only diodes based on poly(2-methoxy, 5-(2′ ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV) were measured at a wide temperature and field range. At high electric fields the temperature dependence of the transport vanishes, and all J-V sweeps converge to a power law. Nuclear tunneling...

Describing the light intensity dependence of polymer:fullerene solar cells using an adapted Shockley diode model

Solar cells are generally optimised for operation under AM1.5 100 mW cm-2 conditions. This is also typically done for polymer solar cells. However, one of the entry markets for this emerging technology is portable electronics. For this market, the spectral shape and intensity of typical illumination conditions deviate considerably from the...

Non-radiative recombination losses in polymer light-emitting diodes

We present a quantitative analysis of the loss of electroluminescence in light-emitting diodes (LEDs) based on poly[2-methoxy-5-(2′-ethylhexyloxy)- p-phenylenevinylene] (MEH-PPV) due to the combination of non-radiative trap-assisted recombination and exciton quenching at the metallic cathode. It is demonstrated that for an MEH-PPV LED the...

Validity of the einstein relation in disordered organic semiconductors

It is controversial whether energetic disorder in semiconductors is already sufficient to violate the classical Einstein relation, even in the case of thermal equilibrium. We demonstrate that the Einstein relation is violated only under nonequilibrium conditions due to deeply trapped carriers, as in diffusion-driven current measurements on...

Trap-assisted recombination in disordered organic semiconductors

The trap-assisted recombination of electrons and holes in organic semiconductors is investigated. The extracted capture coefficients of the trap-assisted recombination process are thermally activated with an identical activation energy as measured for the hole mobility μp. We demonstrate that the rate limiting step for this mechanism is the...

Combined optical and electrical modeling of polymer: fullerene bulk heterojunction solar cells

Optical interference effects are important for the total absorption as well as the profile of the exciton generation rate in polymer:fullerene bulk heterojunction solar cells. For solar cells with an active layer of poly [2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] as electron donor and [6,6]-phenyl C61 butyric acid methyl ester...

Device model for the operation of polymer/fullerene bulk heterojunction solar cells