Chapter 2 is aimed to introduce researchers who are planning to work on organic solar cells into this very specialised but also interdisciplinary field. It also comprises a survey of the interesting transport charge carrier mobility properties of liquid crystalline semiconductors as well as the mesogenic characterization of a series of discotic molecules from which one has been used to fabricate a single layer solar cell.
However, we have also found Organic solar cells phd thesis the shunt resistor grows 30 to times faster than the series resistor with increasing film thickness favouring thicker films for larger fill factors.
Finally, fractional kinetics and generalised diffusion equations are explored. The object of this thesis was the investigation of various types of organic semiconductors preferably with low bandgaps in different solar cell architectures. In fact, this Chapter contains a unique compilation and summary of "organic solar cell relevant knowledge" that is consistent with the experience, understanding and view of the author.
Each of them begins with a survey of characteristic parameters of already reported devices - including the results of this thesis - pointing out specific advantages and encountered problems. Two laminated devices are discussed in Chapter 6.
In Chapter 7 we have shown that dyes with liquid crystalline properties can be used as active semiconducting components in solar cells.
Our results together with the recent literature indicate that heating into the liquid crystalline phase is not necessary. Chapter 7 concerns single layer devices comprising a liquid crystalline semiconductor.
We show that the Poisson summation theorem permits the analytic solution of a fractional diffusion equation to be collapsed into closed form. It is argued instead that dispersive transport arises from the loss of carriers to trap states. In Chapter 8 we describe how the standard solar spectrum can be simulated with a relatively simple setup that can be built in most laboratories for a fraction of the cost of commercial simulators.
The outstanding properties of discotic liquid crystals justify the discussion of this device in a Chapter separated from the single layer device Chapter. We have studied effects of film thickness and have found that those devices that have the thinnest films nm, which is near the estimated exciton diffusion length give the highest currents.
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. How solar cell efficiencies can be determined in a reasonable yet practical way either by setting up a solar simulator or numerical simulation is discussed in Chapter 8.
This is also reflected in the long list of people mentioned in the acknowledgment and consistent with the fact that modern research relies on collaboration and teamwork.
Next, the techniques are extended to recombination measurements, where the recombination coefficient in a benchmark polymer: These experiments demonstrate the absence of "hot carrier" relaxation effects on the timescales of charge transport in several organic photovoltaic polymer: In organic photovoltaics, high efficiencies can only be achieved if charge transport is able to extract charge carriers from the active layer with minimal recombination losses.
All devices discussed in the Chapters on double layer, blends and laminated structures show spectral responses covering at least the wavelength range of visible light. The more general properties of organic semiconductors can be found in many excellent text books and other references and are only summarized briefly in the first part whereas the second part gives a more comprehensive insight into the important characteristic solar cell parameters and links between them.
A method to estimate the optimal thickness has been introduced. This work presents new insights into the measurement of charge transport, the underlying physics, as well as new approaches for modelling. Chapter 9 concludes with a summary of the characteristic parameters comprising all four solar cell architecture, an overall assessment, some suggestions for future investigations and a comprehensive bibliography.
Charge carrier mobility is studied using photogenerated charge extraction by linearly increasing voltage photo-CELIV and the novel technique of resistance-dependent photovoltage RPV. However, the following findings may be of particular interest for both experts and newcomers in the field:University of Wollongong Research Online University of Wollongong Thesis Collection University of Wollongong Thesis Collections Nanostructured organic solar cells.
Qadir, Karwan Wasman () Study of organic semiconductor based photovoltaic devices: light sensors and solar cells / Karwan Wasman Qadir.
This thesis deals with the device physics of organic solar cells. 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.
Complementary Materials for Tandem Organic Solar Cells Jiang, Wei (). Complementary Materials for Tandem Organic Solar Cells PhD Thesis, School of Chemistry & Molecular Biosciences, The University of Queensland. doi: /uql Electrical simulation of organic solar cells.
But if you are interested to write a code yourself, you can use Mr Koster phd thesis: "Device physics of donor/acceptor-blend. Mar 20, · Exciton recombination in bulk heterojunction organic solar cells.
Note: since this defense we finished the research and found that Auger recombination is not.Download