It is therefore crucial to understand the underlying processes determining the photocurrent in order to be able to further improve the solar cell performance. Dimerization is found to be suppressed in the presence of oxygen and is independent of the temperature. Ein weiterer wichtiger, die Leistung einer Solarzelle begrenzender Parameter ist deren Diffusionsspannung built-in potential, VBi. In case of organic bulk heterojunction BHJ solar cells it is — in contrast to inorganic devices — dependent on the applied bias voltage. Finally, the formation of different photogenerated species and their kinetics in PC60BM films and blends with polymer is studied by ultrafast transient absorption spectroscopy.

A variation of the absorption profile within the blend layer shows that the probability of charge-carrier extraction depends on the locus of charge-carrier generation. Experiments and simulations Reinhardt, J. Organic solar cells consist of hydrocarbon compounds, deposited as ultrathin layers some tens of nm on a substrate. On the impact of contact selectivity and charge transport on the open-circuit voltage of organic solar cells Spies, A. The electrical model developed here is combined with an optical model and covers the diffusion of excitons, their separation, and the subsequent transport of charges.

Ein weiterer wichtiger, die Leistung einer Solarzelle begrenzender Parameter ist deren Diffusionsspannung built-in potential, VBi. Title All words At least one word None of the words. Additional Person s All words At least one word None of the words.

Therefore, the J-V curve is selected as means of comparison between systematic series of simulation and experimental data.

Characterization disserttation tandem organic solar cells Timmreck, R.

OPUS Würzburg | Photocurrent in Organic Solar Cells

This dissertation constitutes a detailed study of the degradation behavior of organic photovoltaics under different ambient conditions, with particular focus on the role of the fullerene in all processes. An effective dissociation of excitons is provided by a heterojunction of two molecules with different frontier orbital energies, such that the electron is transfered to the electron acceptor and the positive charge hole remains on the donor molecule.


organische solarzelle dissertation

Thereafter, the optical and electronic properties should be investigated using UV vis spectroscopy and cyclic voltammetry, respectively. Similar studies were also be presented with two modern low bandgap polymers which only differ by the bridging prganische in the cyclopentadithiophene PCPDTBT: It is observed that the open-circuit voltage of these devices depends on the mixing ratio of ZnPc: Extraction of physical parameters by means of markov chain Monte Carlo techniques Raba, A.

Inversion of the layer sequence in organic solar cells – physical and technological aspects

After this macroscopic splarzelle on the photocurrent, the focus of this work moves to the more basic processes determining the photocurrent: That is why several OPV startup companies were launched in the last decade. It is explained by simulated electrical-field profiles why also injection barriers lead to a reduction of the probability for charge-carrier extraction.

One major reason for this boom is a potentially low-cost production of solar modules on flexible polymer substrate. Layout flexibility for sheet-to-sheet produced flexible ITO-free organic solar modules with organic functional layers slot die coated under ambient atmospheric conditions Kaduwal, D.

One crucial issue, as already mentioned, is the contact between absorber layer and electrode.

Externe Quanteneffizienzmessungen an organischen Tandemsolarzellen

Photo-induced absorption spectroscopy reveals that the enhanced degradation of C-PCPDTBT correlates with the population of the polymer triplet state via the polymer: Die entsprechenden Ergebnisse wurden dann in Relation zu den Strom—Spannungs-Kennlinien gesetzt, um die deutlichen Unterschiede in der Effizienz der Solarzellen zu diskutieren.

Referee s All words At least one word None of the words. In a comparative study the field-dependence of these was investigated by time-delayed collection field TDCF measurements for two well-known reference systems, namely P3HT: This work focuses xolarzelle the electrical processes in organic solar cells developing and employing a one-dimensional drift-diffusion model. In addition, clear differences in the nongeminate recombination dynamics of both material systems were found. By this means, we establish a mechanistic understanding of the photo-induced fullerene dimerization in the solid state.


organische solarzelle dissertation

Absorption of light leads to molecular excited states excitons which are strongly bound due to the weak interactions and low dielectric constant in a molecular solid. Energy barriers lead to a reduction of the power-conversion efficiency due to a decrease in the disdertation voltage or the fill factor by S-shaped J-V curve S-kinkwhich are often observed for organic solar cells.

Furthermore, the electronic structure of the A-D-A scaffold should be modified by the replacing the DCV acceptor moieties by 1- 1,1-dicyanomethylene -cyclohexene DCC units, in order to shift the absorption towards longer wavelength for an enhanced organischs harvest. Comparison with standard device architecture Arredondo, B. At Surface states, band structure, electron density of states. A fullerene LUMO level of The current-voltage characteristics J-V curve of a solar cell reflect the electrical processes in the device.

Organic solar cells consist of solarzzelle compounds, deposited as ultrathin layers some tens of nm on a substrate.

Performance of ITO-free inverted organic bulk heterojunction photodetectors: The first approach will be based on oranische previous project dealing with the synthesis of a series of oligothiophenes consisting of an A-D-A system comprising a central dithieno[3: Determining the photocurrent of individual cells within an organic solar module by LBIC and the filtering approach: