Finally, the formation of different photogenerated species and their kinetics in PC60BM films and blends with polymer is studied by ultrafast transient absorption spectroscopy. Controlling the intragap states of electron transporting interlayers for efficient and stable inverted organic photovoltaics Bai, S. On the impact of contact selectivity and charge transport on the open-circuit voltage of organic solar cells Spies, A. High yield fabrication of vertical interdigital electrodes with sub micrometer distance and their application in an organic photovoltaic device Stelzl, F. This results in a fill factor dependent on the absorption profile. Die organische Photovoltaik ist ein Forschungsgebiet, dem in den letzten zehn Jahren enorme Aufmerksamkeit zu Teil wurde.
It is observed that the open-circuit voltage of these devices depends on the mixing ratio of ZnPc: Our electrical, spectroscopic, and analytic measurements on this model system provide evidence that photo-dimerization of PC60BM, i. As it was originally derived for abrupt pn-junctions, its validity for organic BHJ solar cells — a bipolar, effective medium — was discussed. Improved efficiency of bulk heterojunction hybrid solar cells by utilizing CdSe quantum dot-graphene nanocomposites Eck, M. Organic photovoltaics OPV is a field of applied research which has been growing rapidly in the last decade leading to a current record value of power-conversion efficiency of 10 percent.
The physical meaning of charge extraction by linearly increasing voltage transients from organic solar cells Hanfland, R.
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Author s All words At least one word Oranische of the words. 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.
Sooarzelle excitons have to be split into positive and negative charges, which are subsequently collected at different electrodes.
Diese wird im letzten Teil der Arbeit anhand der ZnPc: In flat heterojunction solar cells an additional reason for S-kinks is found in an imbalance of electron and hole mobilities. Therefore, the J-V curve is selected as means of comparison between systematic series of solarzeelle and experimental data.
Another crucial parameter limiting the solar cell efficiency is the builtin potential of a device. 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.
Externe Quanteneffizienzmessungen an organischen Tandemsolarzellen
In the first part of this thesis, we investigate the degradation of organic solar cells under photo-oxidative conditions. Luminescence spectroscopy and thin-film interference effects in organic solar cells: Towards continuous junction CJ organic electronic devices: In addition, clear differences in the nongeminate recombination dynamics of both material systems were found. It solarzellf explained by simulated electrical-field profiles why also injection barriers lead to a reduction of the probability for charge-carrier extraction.
Abstract All words At least one word None of the words. Please always quote using diasertation URN: Positive side of disorder: Extraction of physical parameters by means of markov chain Monte Carlo techniques Raba, A. One major reason for this boom is a potentially low-cost production of oslarzelle modules on flexible polymer substrate. Thereafter, the optical and electronic properties should be investigated using UV vis spectroscopy and cyclic voltammetry, respectively.
A fullerene LUMO level of This work focuses on the electrical processes in organic solar cells developing and employing a one-dimensional drift-diffusion model.
Comparison with standard device architecture Arredondo, B. Such small changes in the chemical structure were already sufficient to affect the charge photogeneration as well as the morphology of the blend. Furthermore, the focus of this work will not only be set on the structure-property relationships of the organizche oligomers, gained through thorough analytical investigations, but also on elucidating valid structure-device property relationships.
Seite drucken Zum Seitenanfang. One idssertation factor influencing the device efficiency is the photocurrent of a solar cell, which is defined as the difference between the current under illumination and in the dark.
It is therefore crucial to understand the underlying processes determining the photocurrent in order to be orgsnische to further improve the solar cell performance. Controlling the intragap states of electron transporting interlayers for efficient and stable inverted organic photovoltaics Bai, S. The most important intrinsic loss mechanism of a solar cell is bulk recombination which is treated at the example of ZnPc: The first one — via a thermalized charge transfer state CTS — is clearly influenced ortanische geminate recombination and therefore less efficient.
Abstract EN This thesis deals with the device physics of organic solar cells.
In this respect, the structure of the best-performing oligomer of the series, which was synthesized during my master thesis, should be further improved in terms of the alkyl-substitution pattern, in order to improve the resulting film microstructure in the bulk-heterojunction and thus, reach higher PCE in solution-processed BHJSC. The first approach will be based on a previous project dealing with the synthesis of a series of oligothiophenes consisting of an A-D-A system comprising a central dithieno[3: It is shown by a systematic study that the introduction of deliberate barriers for charge-carrier extraction and injection can cause such S-kinks.