It is argued instead that dispersive transport arises from the loss of carriers to trap states.
In photovoltaic cells, excitons are broken up into free electron-hole pairs by effective fields.
The effective fields are set up by creating a heterojunction between two dissimilar materials.
Finally, fractional kinetics and generalised diffusion equations are explored. (2011) Analytic solution of the fractional advection-diffusion equation for the time-of-flight experiment in a finite geometry.
We show that the Poisson summation theorem permits the analytic solution of a fractional diffusion equation to be collapsed into closed form.
Subsequently, these techniques are applied to a new type of kinetic model that is capable of unifying normal and dispersive transport within a single framework.
charge extraction; charge transport; diffusion equations; fractional kinetics; high intensity RPV (HI- RPV); intensity dependent photocurrents (IPC); linearly increasing voltage; organic solar cells; photovoltaic cells; photovoltaic power generation; Poisson summation formula; polymers; resistance-dependent photovoltage (RPV); solar cells; solar-photovoltaic energy; superconductivity Publications arising from this thesis are available from the Related URLs field.
The delocalized π orbital is the highest occupied molecular orbital (HOMO), and the π* orbital is the lowest unoccupied molecular orbital (LUMO).
In organic semiconductor physics, the HOMO takes the role of the valence band while the LUMO serves as the conduction band.
Modelling of the steady-state photocurrent produced by a solar cell demonstrates the conditions under which non-geminate recombination may be avoided, and presents a design rule for avoiding non-geminate recombination. Philippa, Bronson, Stolterfoht, Martin, White, Ronald D., Velusamy, Marrapan, Burn, Paul L., Meredith, Paul, and Pivrikas, Almantas (2014) Molecular weight dependent bimolecular recombination in organic solar cells. Philippa, Bronson, Stolterfoht, Martin, Burn, Paul L., Juška, Gytis, Meredith, Paul, White, Ronald D., and Pivrikas, Almantas (2014) The impact of hot charge carrier mobility on photocurrent losses in polymer-based solar cells.
Experimental measurements on devices of varying thickness support the conclusion that the space-charge limited current is a fundamental threshold for high-efficiency photocurrent extraction.