Hybrid organic-inorganic solar photovoltaic (PV) cells capable of directly converting sunlight to electricity have attracted much attention in recent years. Despite evident technological advancements in the PV industry, the widespread commercialisation of solar cells is still being mired by their low conversion efficiencies and high cost per Watt. Perovskites are an emerging class of semiconductors providing a low-cost alternative to silicon-based photovoltaic cells, which currently dominate the market. This thesis develops a series of studies on “all-solid state perovskite solar cells” fabricated via vapour deposition which is an industrially-accessible technique, to achieve planar heterojunction architectures and efficient PV devices. Chapter 2 presents a general outlook on the operating principles of solar cells, delving deeper into the specific operational mechanism of perovskite solar cells. It also explores the usual methods employed in the fabrication of perovskite thin films. Chapter 3 describes the experimental procedures followed during the fabrication of the individual components constituting the device from the synthesis of the precursors to the construction of the functioning perovskite PV devices. Chapter 4 demonstrates pioneering work involving the dual-source vapour deposition (DSVD) of planar heterojunction perovskite solar cells which generated remarkable power conversion efficiency values surpassing 15%. These significant results pave the way for the mass-production of perovskite PVs. To further expand the range of feasible vapour deposition techniques, a two-layer sequential vapour deposition (SVD) technique is explored in Chapter 5. This chapter focusses on identifying the factors affecting the fundamental properties of the vapour-deposited films. Findings provide an improved understanding of the effects of precursor compositions and annealing conditions on the films. Chapter 5 concludes with a comparison between SVD and DSVD fabricated films, highlighting the benefits of each vapour deposition technique. Furthermore, hysteretic effects are analysed in Chapter 6 for the perovskite PV devices fabricated based on different structural configurations. An interesting discovery involving the temporary functioning of compact layer-free perovskite PV devices suggests the presence of a built-in-field responsible for the hysteresis of the cells. The observations made in this chapter yield a new understanding of the functionality of individual cell layers. Combining the advantages of the optimum vapour deposition technique established in Chapter 4 and Chapter 5, with the enhanced understanding of perovskite PV cell operational mechanism acquired from Chapter 6, an ongoing study on an “all-perovskite” tandem solar cell is introduced in Chapter 7. This demonstration of the “all-perovskite” tandem devices confirms the versatility of perovskites for a broader range of PV applications.

<p>Solution chemistry is a versatile and powerful tool in the synthesis of designed, complex nano-level high-tech materials. Normally, the technique is considered too expensive for large-scale production of complex multi-component ceramic materials. This thesis describes the expansion of the useful area of solution processing to multi-component bulk materials such as ZnO-based high-field varistors and WC–Co cutting tools, by developing novel techniques for solution-based coating of conventionally prepared metal and ceramic powders. The chemistry and microstructure development in the preparation of coatings, and the sintering of the coated powders to compacts, were studied in detail by SEM-EDS, TEM-EDS, XRD, IR-spectroscopy, dilatometry, TGA and DSC chemical analysis. </p><p>ZnO powder with a ca 20 nm thick, homogeneous oxide coat of Bi–Sb–Ni–Co–Mn–Cr–Al oxide was prepared. After sintering to dense varistor bodies, much improved microstructures with much reduced ZnO-grain sizes were obtained. This shows that the oxides added as liquid sintering aid and grain-growth inhibitor become much more active when added homogeneously as a skin on the ZnO powder.</p><p>After sintering of cobalt-coated WC, much improved micro-structures were obtained with a much more narrow WC grain-size distribution than that obtained from starting powders mixed by a conventional milling route. Coated powders also obviate the need for the extensive milling of WC and Co powders used in conventional mixing.</p><p>The novel solution route was also applied to preparation of porous sponges and thin films on metal, glass and Al₂O₃ of sub 20 nm sized Co- or Ni-particles. </p>

<p dir="ltr">With climate change creating the need for renewable energy to replace fossil fuels, solar energy technologies are primed to dominate the energy sector. And while photovoltaics have improved significantly in recent decades, continued evolution of this technology requires research into new fabrication techniques and new materials. The solution processing of metal chalcogenide semiconductors offers an opportunity to fabricate photovoltaics in a low-cost and high-throughput way. However, for this methodology to make a commercial impact a variety of challenges around the fundamental chemistry and materials science need to be addressed. Furthermore, while solution processing has been applied heavily to the Cu(In,Ga)(S,Se)₂ family of materials, these techniques can also open doors for emerging materials like Cu₂ZnSnSe₄, Ag₂ZnSnSe₄, and the chalcogenide perovskites.</p><p dir="ltr">In solution processed Cu(In,Ga)(S,Se)₂ devices, researcher have generally started with a Cu(In,Ga)S₂ film that is then selenized to form the final Cu(In,Ga)(S,Se)₂ material. However, this process has been connected to the formation of a problematic “fine-grain” layer. To solve this issue, the molecular precursors from amine-thiol chemistry were modified to produce soluble molecules with metal selenium bonding. This enabled direct solution deposition of CuInSe₂ films that could be processed without forming a fine grain layer.</p><p dir="ltr">Reactive dissolution chemistry (or “alkahest” chemistry) is useful for solution processing because it can enable the direct use of metal or metal chalcogenide precursors, bypassing the potential impurities from metal salt precursors. However, the commonly used amine-thiol reactive solvent system is better suited to making metal sulfides than metal selenides because the thiol acts as a sulfur source. To address this limitation, a new alkahest based on alkylammonium polyselenide solutions was developed which could reactively dissolve a wide range of metals, metal chalcogenides, and metal oxides. This generalizable chemistry enabled the synthesis of a wide range of binary and multinary metal chalcogenides including Cu(In,Ga)Se₂, Cu₂ZnSnSe₄, and Ag₂ZnSnSe₄.</p><p dir="ltr">Emerging metal chalcogenide semiconductors composed of earth-abundant and non-toxic elements that can exhibit strong optoelectronic properties and high stability are a target of significant interest. Chalcogenide perovskites like BaZrS₃ and BaHfS₃ are an intriguing option to satisfy these requirements but have rarely been studied because of synthesis difficulties, historically being made by solid-state reactions or the sulfurization of oxides around 1000 °C. Here a solution-based approach that only requires moderate temperatures of 550-575 °C was developed utilizing a hybrid ink containing soluble metal thiolates and nanoparticulate metal hydrides.</p><p dir="ltr">The hybrid ink was an important proof of concept that chalcogenide perovskites could be synthesized at these moderate temperatures. However, it relies on complex and difficult to handle precursors. A simpler route would be to use air-stable precursors to make an oxide perovskite and subsequently sulfurize the material. However, this route has historically used excessively high temperatures. Therefore, a new sulfurization step was conceived based on thermodynamic arguments that includes both sulfur and hafnium sulfide as an oxygen sink. This redesigned sulfurization enabled the conversion of BaZrO₃ into BaZrS₃ at temperatures around 575 °C.</p><p dir="ltr">Finally, an energy systems and economic analysis was performed to consider how photovoltaics might be incorporated into agricultural lands. This work showed that when compared with traditional photovoltaics or a PV Aglectric concept, using corn for ethanol is an inefficient way to generate both food and energy from a given unit of land.</p>

Small angle X-ray scattering (SAXS) has been widely used in polymer science to study the nano-scale morphology of various polymers. The data obtained from SAXS give information about sizes and shapes of macromolecules, characteristic distances of partially ordered materials, pore sizes, and so on. The understanding of these structural parameters is crucial in polymer science in that it will help to explain the origin of various properties of polymers, and guide design of future polymers with desired properties. We have been able to further develop the contrast variation method in SAXS to study the morphology of Nafion 117CS containing different alkali metal ions in solid state. Contrast variation allows one to manipulate scattering data to obtain desired morphological information. At room temperature, only the crystalline peak was found for Na⁺-form Nafion, while for Cs⁺-form Nafion only the ionic peak was observed. The utilization of one dimensional correlation function on different counterion forms of Nafion further demonstrates the necessity of contrast variation method in obtaining more detailed morphological information of Nafion. This separation of the ionic peak and the crystalline peak in Nafion provides a means to independently study the crystalline and ionic components without each other's effect, which could be further applied to other ionomer systems. We also designed time resolved SAXS experiments to study the morphological development during solution processing Nafion. As solvent was removed from Nafion dispersion through evaporation, solid-state morphological development occurred through a variety of processes including phase-inversion, aggregation of interacting species (e.g., ionic functionalities), and crystallization of backbone segments. To probe the real-time morphological development during membrane processing that accurately simulates industrial protocols, a unique sample cell has been constructed that allows for through-film synchrotron SAXS data acquisition during solvent evaporation and film formation. For the first time, this novel experiment allows for a complete analysis of structural evolution from solution/dispersion to solid-state film formation, and we were able to show that the crystallites within Nafion develop later than the formation of ionic domains, and they do not reside in the cylindrical particles, but are dispersed in solution/dispersion. Besides bulk morphology of Nafion, we have also performed Grazing Incident SAXS to study the surface morphology of Nafion. We were able to manipulate the surface morphology of Nafion via neutralizing H⁺-form Nafion with different large organic counterions, as well as annealing Nafion thin films under different temperatures. This not only allows to obtain more detailed information of the nano-structures in Nafion thin films, but also provides a means to achieve desired morphology for better fuel cell applications. We have also been able to study the polymer chain conformation in solution via measuring persistence length by utilizing solution SAXS. Different methods have been applied to study the SAXS profiles, and the measured persistence lengths for stilbene and styrenic alternating copolymers range from 2 to 6 nm, which characterizes these copolymers into a class of semi-rigid polymers. This study allows to elucidate the steric crowding effect on the chain stiffness of these polymers, which provides fundamental understanding of polymer chain behaviors in solution. Self-assembling in block copolymers has also been studied using SAXS. We established a morphological model for a multiblock copolymer used as a fuel cell material from General Motors®, and this morphological model could be used to explain the origins of the mechanical and transport properties of this material. Furthermore, several other block copolymers have been studied using SAXS, which showed interesting phase separated morphologies. These morphological data have been successfully applied to explain the origins of various properties of these block copolymers, which provide fundamental knowledge of structure-property relationship in block copolymers. / Ph. D.

Organic light-emitting diodes (OLEDs) have drawn much attention in the last two decades. In recent years, the power efficiency of OLEDs has been increased to exceed the efficiency of fluorescent light bulbs. However, such high-efficiency devices are typically based on small molecules that have to be evaporated in vacuum. A much higher fabrication throughput and therefore lowered costs are expected if high-efficiency OLEDs were processed from solution. This thesis shows how solution-processed electrophosphorescent multilayer OLEDs can be achieved by starting with an evaporated three-layer device structure and replacing layer by layer with a solution-processed layer. First, the hole-transport layer was replaced by a polymer and high efficiencies were observed when using a hole-transport polymer with a high ionization potential and a low hole mobility. Then, the emissive layer was replaced by a copolymer consisting of hole-transport groups and emissive complexes in its side-chains. OLEDs with four different colors are shown where the orange devices showed the highest efficiency. The orange copolymer was further optimized by making changes to the chemical nature of the polymer, such as different molecular weight, different concentrations of the emissive complex and different linkers between the side-chains and the polymer backbone. Finally, a three-layer solution-processed OLED was fabricated by crosslinking the hole-transport and the emissive layer, and by spin-coating an electron-transport polymer on top. Moreover, using the photocrosslinking properties of the emissive layer, solution-processed multilayer OLEDs of two different colors were patterned using photolithography to fabricate a white-light source with a tunable emission spectrum. Furthermore, with more and more organic semiconductors being integrated into the circuitry of commercial products, good electrical models are needed for a circuit design with predictive capabilities. Therefore, a model for the example of an organic single-layer diode is introduced in the last chapter of this thesis. The model has been implemented into SPICE and consists of an equivalent circuit that is mostly based on intrinsic material properties, which can be measured in independent experiments. The model has been tested on four different organic materials, and good agreement between model and experimental results is shown.

Une cellule photovoltaïque organique (OPV) consiste en un empilement de couches minces et comporte une électrode transparente, constituée le plus souvent par une couche mince d’oxyde d’indium dopé à l’étain (ITO). Des matériaux alternatifs sans indium, déposables par voie liquide à l’air ambiant, et sur de grandes surfaces souples plus adaptées à la filière OPV, sont actuellement l’objet d’un grand nombre de recherches. Les nanofils d’argent (Ag NWs) représentent un sérieux candidat pour remplacer l’ITO et sont l’objet de ce travail de thèse. Une méthode de dépôt des Ag NWs par spray à air sur des substrats de PET a été développée en vue de réaliser des films conducteurs et transparents sur une grande surface souple. Puis ces électrodes transparentes ont été intégrées dans des cellules OPV sur substrat souple avec des rendements comparables à l’ITO. Les dépôts par voie liquide ont été privilégiés (spray-coating, Dr Blade), excepté pour l’électrode supérieure en argent, évaporée sous vide. Enfin les cellules ont été interconnectées en série pour former un module OPV, plus efficace en termes de puissance électrique délivrée. Une étude sur l’ablation sélective de couches de l’empilement OPV par laser est également présentée pour la fabrication de modules. / An organic photovoltaic (OPV) cell consists of a thin-layer stack which includes a transparent electrode, usually made of indium tin-doped oxide (ITO). Alternative, indium-free materials, deposited in air with a wet deposition process on large, flexible substrates that are more compatible with the OPV field are currently widely investigated. Silver nanowires (Ag NWs), which represent a serious candidate to replace ITO, are the subject of this thesis. In this work a method to deposit Ag NWs on PET substrates by air spray-coating has been developed : efficient patterned conductive and transparent coatings could be processed on a large, flexible substrate. This transparent electrode was then integrated in flexible and large area OPV cells, with efficiencies comparable to ITO. Wet deposition techniques were preferred except for the silver top electrode, evaporated under vacuum. OPV cells were eventually interconnected in series in order to make an OPV module, delivering a higher electrical output. A study on selective laser ablation of layers in the OPV stack is also shown towards module processing.

<p> </p> <p>Combating climate change requires society to shift to using clean, renewable sources of energy as quickly as possible. Photovoltaics (PVs) are a promising source of renewable energy due to the broad availability of solar radiation over the Earth’s surface and the low cost of PV modules. While silicon solar cells dominate the current PV market, some drawbacks motivate the search for other solar materials. Silicon’s indirect band gap necessitates using<br> thick (>100 μm) absorber layers which limits applications to rigid substrates, and manufacturing silicon wafers suitable for solar cell applications requires slow batch processes,<br> hindering the rapid deployment of PV technology.</p> <p><br> One opportunity for realizing rapid manufacturing of PV modules is solution processing, wherein a solar cell is deposited with the use of liquid solutions containing the necessary constituent elements. A solution processing approach could be done in a roll-to-roll format in which a flexible substrate is coated at high speed to create a thin, flexible PV device. Such an approach is expected to dramatically increase the throughput capability of a photovoltaic manufacturing line. To realize the benefits of solution processing, suitable liquid-phase chemistries must be developed to enable the deposition of the desired absorber material while minimizing the incorporation of undesirable contaminants. One such approach is the<br> amine-thiol solvent system which is notable for its ability to solubilize not only metal salts, but also metal sulfides, metal selenides, and pure metals. This makes the amine-thiol system a promising candidate for the deposition of metal chalcogenide absorber layer materials.</p> <p><br> In this work, the chemistry of the amine-thiol system is studied in detail and reaction mechanisms governing the interaction of amine-thiol solutions with precursors relevant to the Cu(In,Ga)(S,Se)2 material system are investigated. Nuclear Magnetic Resonance, Mass Spectrometry, and X-Ray Absorption measurements are performed to study this system. Structures for the metal thiolate species that form in these reactions are proposed, along with the products of the pyrolysis reaction that converts the thiolate species to the desired metal sulfides. The utility of this understanding is discussed.</p> <p><br> The amine-thiol system is further applied to the synthesis of AgIn(S,Se)2, a material with some similarities to the more common metal chalcogenide CuInSe2 but studied far less<br> thoroughly. The material and optoelectronic properties of AgIn(S,Se)2 are characterized. X-Ray Diffraction, Hall Effect Measurements, Kelvin Probe Force Miscropscopy, and Quantitative Photoluminescence are all performed on AgIn(S,Se)2 thin films. AgIn(S,Se)2 films are found to exhibit high carrier mobility, benign grain boundaries, and strong photoluminescence emission, suggesting that AgIn(S,Se)2 may function as an effective absorber layer<br> material for thin-film solar cells. Challenges facing its successful adoption as a solar cell material as discussed.<br> </p> <p>In this work, a novel method is developed to calibrate photoluminescence spectrometers for absolute photon counts, enabling one to calculate the absolute number of photons leaving a photoluminescence sample. This enables an estimation of the Quasi-Fermi Level Splitting of an absorber layer (and hence open-circuit voltage of a solar cell) while only measuring a bare absorber layer film. The experimental method and required numerical analysis of the<br> data are described herein.</p>

Perovskite solar cells have garnered significant interest thanks to the impressive rise of their efficiency over the last few years to a power conversion efficiency (PCE) of 25.2% despite being processable using cheap and potentially high-throughput solution coating techniques. Using the two-step conversion process high-quality perovskite films with high quality and uniformity can be produced, however, this process still needs a deeper and fundamental understanding. This thesis has shed light on the ink-to-solid conversion during the two-step solution process of hybrid perovskite formulations. We demonstrated that the conversion of PbI2 to perovskite is largely dictated by the state of the PbI2 precursor film in terms of its solvated states. We used several in situ diagnostic measurments such as grazing incidence wide-angle x-ray scattering (GIWAXS), quartz crystal microbalance with dissipation monitoring (QCM-D), and optical reflectance and absorbance all performed during spin coating, to monitor the nucleation and growth of crystalline phases, the mass deposition at the solid-liquid interface and the rigidity as well as the solution thinning behavior and the changes in optical absorbance of the precursor and perovskite. We compare conversion behaviors from different lead states by using methylammonium iodide (MAI), formamidinium iodide (FAI), and/or mixtures of halides (I, Br) and show that conversion can occur spontaneously and quite rapidly at room temperature without requiring further thermal annealing. We confirm this by demonstrating improvements in the morphology, microstructure and optoelectronics properties of the resulting perovskite films, as well as their impact on the PCE of solar cells using complimentary measurements such as scanning electron microscopy (SEM), X-ray diffraction (XRD) and with steady-state photoluminescence.

<div>Global warming poses an existential threat to humanity and is inevitable unless significant efforts are made to eliminate its root causes. The need to replace fossil fuels with renewable sources has been obvious for many years, yet the world still receives the vast majority of its energy from non-renewable reservoirs. Harnessing solar radiation is the most promising route to ensure a carbon-free energy future, as the sun is the sole source of energy that can meet humankind’s energy demands for generations to come.<br></div><div><br></div><div>The most widely recognized technology associated with the sun is a photovoltaic (PV) cell, which converts electromagnetic radiation directly into electricity that can either be used immediately or stored for later use. Silicon-based solar cells currently dominate (>90% market share) the global PV market, driven in part due to parallel research in the microelectronics industry. However, silicon is an indirect bandgap material, resulting in inflexible solar modules, and it requires high capital expenditures and high energy inputs for terawatt scale manufacturing.</div><div><br></div><div>The remainder of the commercial PV market consists of thin-film technologies based on Cu(In,Ga)Se₂ (CIGSe) and CdTe. These materials have a direct bandgap, so they can be used in flexible applications, and they are readily scalable due to their amenability to low-cost, roll-to-roll manufacturing. The power conversion efficiencies of CIGSe and CdTe cells have exceeded 20% and are nearing those of silicon cells, but concerns over the long-term supply of indium and tellurium cast doubt on whether these materials can be deployed at large scales. Alternative materials, such as Cu₂ZnSnS_4-xSe_x (CZTSSe), have been researched for many years; the allure of a material with earth abundant elements and properties similar to CIGSe and CdTe was quite enticing. However, recent work suggests that CZTSSe is fundamentally limited by the formation of defects and band tails in the bulk material, and the efficiencies of CZTSSe-based devices have been saturated since 2013.</div><div><br></div><div>New materials for the PV market must meet several criteria, including constituent earth abundant elements, outstanding optoelectronic properties, and low propensity for defect formation. In this regard, the copper-arsenic-sulfur family of materials is an attractive candidate for PV applications. Cu, As, and S are all earth abundant elements with sufficiently different ionic radii, suggesting high defect formation energies. In addition, previous computational work has suggested that several ternary phases, most notably enargite Cu₃AsS₄, have appropriate bandgaps, high absorption coefficients, and high predicted efficiencies in a thin-film PV device. The system must be investigated experimentally, with attention not only paid to synthesis and device performance, but also to characteristics that give clues as to whether high efficiencies are achievable.</div><div><br></div><div>This dissertation studies the Cu-As-S system in the context of thin-film photovoltaics, with an emphasis on Cu₃AsS₄ and detours to related materials discussed when appropriate. The first synthesis of Cu₃AsS₄ thin-films is reported using solution-processed nanoparticles as precursors. Initial device efficiencies reach 0.18%, which are further boosted to 0.35% through optimization of the annealing procedure. Several limitations to the initial approach are identified (most notably the presence of a carbonaceous secondary phase) and addressed through post-processing treatments and ligand exchange. Cu₃AsS₄ is also rigorously characterized using a suite of optoelectronic techniques which demonstrate favorable defect characteristics that motivate continued research. The current limitations to Cu₃AsS₄ performance stem from improper device architecture rather than material properties. Further development of Cu-As-S thin films must focus on identifying and fabricating ideal device architectures in parallel with continued improvements to film fabrication.</div><div><br></div><div>This dissertation ultimately demonstrates high promise for Cu₃AsS₄ as a thin-film PV material. It also may serve as an example for other researchers studying new materials, as the examination of fundamental optoelectronic properties early in the material’s development phase is key to ensure that limited scientific resources are invested into the compounds with the highest potential impact on society.<br></div>

Organische Leuchtdioden weisen, verglichen mit anorganischen Leuchtdioden, viele Vorteile auf. So sind sie nicht nur energiesparender, sondern können auch in neuen flexiblen Technologien verwendet werden. Um ihr volles Potenzial auszuschöpfen, können zusätzliche Schichten und neue Materialien hinzugefügt werden. Der Ersatz spröder Elektroden durch dünne Metallschichten kann OLEDs flexibler machen, Zwischenschichten verbessern den Ladungstransport und neuartige Materialien können die Lösungsprozessierung von OLEDs vereinfachen. In den Kapiteln dieser Arbeit wurden je ein Ansatz zur Steigerung der Leistung von OLEDs untersucht. Es wurden dünne Silberschichten aus einer partikelfreien Silbertinte mittels Tintenstrahldruck hergestellt und ihre optischen sowie elektrischen charakterisiert. Die gedruckten Elektroden zeigen eine hohe Biegefestigkeit, bei gleichbleibend guten elektrischen Eigenschaften. Die damit hergestellten Leuchtdioden übertreffen in ihrer Effizienz Referenzdioden mit Indium Zinn Oxid Elektroden. Um die Effizienz organischer Leuchtdioden weiter steigern zu können wurden anschließend Zwischenschichten untersucht. Mittels einer gemischten Schicht aus Zinkoxid und einem Polymer konnte die Effizienz von invertierten Leuchtdioden signifikant gesteigert werden. Weiterhin wurden zwei neu synthetisierte Moleküle dazu verwendet, um die Benetzung von Perowskiten auf Elektroden zu verbessern und somit ihre Herstellbarkeit mittels Tintenstrahldruck zu ermöglichen. Abschließend wurde das Quervernetzen von Polymeren zur Herstellung von Mehrschichtsystemen erforscht. Hierbei wird ein die Löslichkeit eines Polymers durch verschiedene Ansätze verringert. Anhand des lichtemittierenden Polymers Super Yellow wurde dies demonstriert. Die Beständigkeit einer Schicht aus Super Yellow gegenüber Toluol konnte erfolgreich stark erhöht werden. Somit wurde eine nachfolgende Prozessierung einer zusätzlichen Schicht aus demselben Lösungsmittel ermöglicht. / Organic light-emitting diodes have many advantages compared to their inorganic counterparts. Not only can they be used more energy-efficiently, but they can also be used in new, flexible technologies. To reach their full potential, additional layers and new materials can be added. Replacing brittle electrodes with thin metal layers can make OLEDs more flexible, intermediate layers improve charge transport, and novel materials can simplify solution processing of OLEDs. In each of the chapters of this thesis, an approach to increasing the performance of OLEDs was examined. Thin silver layers were produced from a particle-free silver ink using inkjet. Their optical and electrical properties were characterized. The printed electrodes show a high flexural strength while retaining good electrical properties. The efficacy of the light-emitting diodes produced in this way exceeds that of reference diodes. To be able to further increase the efficiency of organic light-emitting diodes, intermediate layers made of new material combinations were subsequently investigated. The efficiency of inverted light-emitting diodes could be significantly increased by means of a blend intermediate layer made of zinc oxide and a polymer. Furthermore, two newly synthesized molecules were used to improve the wetting of perovskites on electrodes and thus enable their manufacturability using inkjet printing. Finally, crosslinking of polymers to fabricate multilayer devices was investigated. Here, the solubility of a polymer is reduced by various approaches. This principle was demonstrated using the light-emitting polymer Super Yellow. The resistance of a layer of Super Yellow against toluene was successfully reduced significantly. Thus, subsequent processing of an additional layer from the same solvent was made possible.