Despite the fact of the outstanding efficiency of the perovskite-based devices, their current size is around a few square millimeters. The application of this thin-film technology in module scale requires an interconnection with optimal laser processing to create a channel for the photo current. In this project, the relation between each film material and the laser beam is analyzed. Furthermore, this scribing process is applied to a workingmodule manufacturing. A semi transparent triple cation-based perovskite module scribing processing has been studied. An n-i-p structure was used for the device. 200 nm indium tin oxide films were used as the front and back electrode, to guarantee the transparency. Spin deposited layers of tin oxide and spiro- OMeTAD were used as the n-type and p-type layers, respectively. A buffer layer between the hole transmitting film and the anode was applied to enhance the performance; for this purpose, a 20 nm molybdenum oxide layer is vapor-deposited. This architecture had a performance of 10.95 % for a single cell, and 4.06 % for a six cells module in front illumination. The laser system is set to work in the UV range with 1 ps pulse length, 10 kHz frequency and apparent power from 1300 to 1800 for scribing speed between 30 to 60 mm/s. To further improve the performance of the module, it was illuminated from the rear side, achieving a 5.9 % efficiency. The results shows a promising outlook for this technology for novel applications, such was in tandem cell applications.

With advancements in the photovoltaics (PV) market, involving increased PV module efficiency and reduced costs, the logical progression is the integration of PV into various surfaces, including vehicles (VIPV). For a driving VIPV, the constant change in irradiance presents a significant challenge. The location, weather, and time are key factors that affect the irradiance prediction. An accurate prediction of solar energy generation is crucial for realizing the full potential of VIPV. In this study, the incident irradiance loss is referred to as shading loss. This thesis is conducted in collaboration with Delft University of Technology (TU Delft) and the Netherlands Organisation for Applied Scientific Research (TNO). TNO has an existing shading loss model that accounts for the surrounding obstructions and weather effects using a fixed value, where the only variable input is the day of the year. On average, it assumes 27% shading losses yearly. This study has improved TNO’s VIPV shading assessment by incorporating more variables into a new model, thereby contributing to a better estimation of the VIPV energy yield. The inputs of the new model are based on key factors causing irradiance loss, where location data is obtained using a Digital Surface Model (DSM). The new contribution to the DSM-based approach is the Web Coverage Service (WCS), which retrieves height data directly through a URL, eliminating the need for the previous manual operations and building upon the model’s scalability. The improved model determines shading losses along a route using two varying shading indicators: Sky View Factor (SVF) and Shading Factor (SF). It can input various irradiance datasets, including or excluding weather effects, and precisely determines the Sun’s position based on the time and day of the year. The DSM-based approach is validated using a dynamic and static validation dataset, with a SVF≤1. The accurate representation of surrounding obstructions during validation contributes to a good-quality model. Both validation studies differ in inputs based on location, time, and weather conditions. The differences in measured and simulated irradiance values are larger in the dynamic dataset than in the static dataset. Deviations are caused by uncertainties and errors, such as local weather effects, sensor inaccuracies, traffic shading, and LiDAR discrepancies, which is the inability to simulate open or changing structures. Weather variability is the primary factor affecting model quality in this validation study, resulting in no fixed inaccuracy factor for model validity. The validated model can accurately represent the environment, but weather variability should be minimized when comparing measured and simulated irradiance. Therefore, averaging is chosen to compare results in this work as it removes unknown or untraceable data points. Beyond previous research studies, this work focuses on two public transport case studies, given the systematic routing with a fixed timetable. The first case study includes a car and a bus, and the second, more extensive case study focuses solely on buses. The choice of inputs in both case studies centers on key factors influencing VIPV irradiance loss. In the Bus 40 study, simulations under clear sky conditions and a fixed time around solar noon resulted in shading losses of 22.7% for the bus and 27.7% for the car. Moreover, the simulated shading loss shows a 2.6% relative difference compared to the yearly average TNO value. For the case study considering 27 bus routes in Amsterdam, simulations are performed using averaged KNMI irradiance and all hours a day, where the annual average shading loss resulted in 24.8%. The SF and clear sky irradiance correlate in the first case study and the SVF and average KNMI irradiance correlate in the second case study. However, using clear sky conditions and uniform overcast conditions does not represent realistic weather conditions and leads to a bias in the correlation. Moreover, classified terrain types do not correlate with SVF, in contrast to the reversed approach by Araki et al. Finally, the model can effectively characterize the shading losses on the route level. However, this methodology falls short when reaching finer resolution, such as when examining smaller route segments or partial shading. The determination of shading losses at the route level can be of further benefit to various stakeholders, such as bus operators who want to determine the optimal bus routes for maximum solar energy generation. In addition, this model can be helpful for policymakers, to predict the required charging infrastructure in a scenario when vehicles are equipped with solar panels. Moreover, this model improves shading loss estimation by accepting a range of datasets instead of TNO’s current approach. By inputting irradiance data for clear skies to complete overcast skies, the shading losses can be predicted in a safer range instead of over- or underestimation based on one shading value.

With the integration of solar panels in urban areas, where shading is a common issue, it is desired to realize more shade-resilient designs. A DC-DC boost converter is an electronic device that can be used for maximum power point tracking (MPPT). When implementing MPPT at sub-module level, the shade resilience of the module can be increased. This thesis aims to investigate the feasibility of implementing planar inductors into c-Si solar cells using the numerical simulation software COMSOL Multiphysics®. Through simulations, the inductance and resistance values for various planar coil geometries were obtained. Subsequently, the feasibility of using these coils in a sub-module DC-DC boost converter was investigated. For this study, a specific case was assumed where a Gen 2 Cell - 160 mm c-Si cell is used with a DC-DC boost converter with a duty cycle of 0.5 and a current ripple of 20%. Given the parameters from these devices, the minimum required inductance of 1.20 μH for a frequency of 200 kHz and 2.40 μH for a frequency of 100 kHz were obtained. The series resistances that can be added to the solar cell while still maintaining high efficiency, range from 1.0 mΩ to 4.8 mΩ, for a 1% to a 5% power loss, respectively. This is all for single-cell power conversion. Two different approaches have been examined; the screen-printed coil(s) approach and the screen printing thickness exceeding coil(s) approach. The former studies coils that do not exceed the maximum thickness achievable with screen printing. As such, these coils could be simpler to implement into a solar cell production line than coils with a higher thickness. In this research, for thicknesses below 300 μm a best-case scenario is studied where the skin effect is neglected. The latter studies a larger range of thicknesses, not taking any specific production method into account, but the skin and proximity effect is taken into account. The screen-printed approach is limited to a thickness range of 10 μm to 200 μm, thus simulated by the 2D model. For the air-core single-cell inductors for DC-DC boost converter applications, the inductance and resistance values were either below the 1.20 μH threshold or above the 4.8 mΩ threshold, respectively. These thresholds change depending on the number of series-connected cells. The inductance of a planar inductor can be boosted up to 200% when adding a magnetic material in a sandwich structure, however, this will also increase the costs of the application. In a boosted-inductance case, the 3-turn coil with a thickness of 200 μm, and a 5% power loss is the only configuration that is feasible for a 200 kHz DC-DC boost converter application, with an inductance of 1.569 μH and a resistance of 3.45 mΩ. By increasing the number of coils per cell, the power dissipation in the coils can be reduced. Using this approach, six feasible topologies can be created. One of those is the nine parallel-connected 8-turn coils with a thickness of 200 μm, reaching an inductance of 1.210 μH and a resistance of 3.186 mΩ, allowing for a 200 kHz DC-DC boost converter application without any magnetic inductance increase. All six options are feasible for integration on a single cell using screen printing, however, the actual resistances will be higher due to the skin and proximity effect, and single-cell integration will be too expensive for industrial applications. When studying thicknesses above the screen printing limit, only the 4-turn coil with a thickness of 300 μm, a magnetically increased inductance of 2.718 μH, and a resistance of 4.01 mΩ, is feasible for the 100 and 200 kHz frequencies. This case however does neglect the skin effect. For the 3D model and thicknesses above 400 μm, the skin effect significantly impacts the resistance. When series connecting multiple cells to a single coil, the only feasible option is the eight-cell connected 8-turn coil for a thickness of 200 μm and 300 μm, both reaching a magnetically increased inductance of 10.431 μH and resistance of 23.33 mΩ and 15.56 mΩ, respectively.

Lightweight PV modules offer a solution to the constructional weight limitations of rooftops. PV modules made by Solarge are considered as one the lightweight PV module solutions. The aim of this thesis project is to analyse and compare the thermal- and electrical behaviour of the polymer modules with glass modules. Also, the thermal- and electrical behaviour of polymer modules with a white backsheet are compared with polymer module containing a black backsheet. First, an experimental setup was designed and installed. The PV modules selected for the installation were polymer and glass PV modules both containing half-cut cells. The white- and black backsheet polymer modules contained full PV cells. All PV modules had a pre-installation check with separate electroluminescence and indoor I-V measurements to determine the performance values under standard test condtions. The first thermal- and electrical behaviour comparison was performed for the polymer- and glass modules over the period of 1 June till 30 September. It was found that increasing wind speed affects the cell temperature of glass modules most compared to the polymer modules. On the other hand, the level of irradiance affects most the cell temperatures of the polymer modules. Overall, it was found that the solar weighted average cell temperature was higher for the polymer modules, 39.1 - 39.3∘𝐶, compared to the glass modules, 36.9 - 37.2∘𝐶. Regarding the electrical behaviour, it was found that the mean energy yield of the polymer modules was 4.69% lower compared to the mean energy yield of the glass modules. Also the the glass modules had a higher daily performance ratio, 91.5 - 92.2%, compared to the polymer modules, 87.5 - 87.7%. Part of the difference in energy yield and performance ratio origins in the higher cell temperature for the polymer modules. However, a normalised current difference was found as well, that root in optical losses. The second thermal- and electrical behaviour comparison was performed for the white backsheet and black backsheet polymer modules over the period of 1 June till 30 September. It was found that increasing wind speed affects the cell temperature of black backsheet polymer modules most compared to the white backsheet polymer modules. On the other hand, the level of irradiance affects the cell temperatures of the white backsheet- and black backsheet polymer modules with a comparable heating slope. Overall, it was found that the solar weighted average cell temperature was comparable with 8.3 - 38.7∘𝐶 for the white backsheet polymer modules and 38.1 - 38.7∘𝐶 for the black backsheet polymer modules. Regarding the electrical behaviour, it was found that the mean energy yield of the white backsheet polymer modules was 1.54% higher compared to the mean energy yield of the black backsheet polymer modules. Also, the white backsheet polymer modules had a higher daily PR, 87.7 - 89.1%, compared to the black backsheet polymer modules, 86.8 - 87.8%. The small difference in performance was not directly found in the normalised current and voltage. Measurement uncertainties are therefore seen as a possible root for this difference.

Monofacial modules capture light that falls on the front side of the module, and convert the solar energy to electricity. Bifacial modules can also capture the light that falls on the rear side of the module. For free standing bifacial modules, this results in a power output increase of 5 to 30% compared to monofacial modules. However, due to the heat generation by rear irradiance, this gain is partly lost. In this work, the effect of cell architecture (bifacial/monofacial) and module layout (bifacial/monofacial) on how much modules heat up under outdoor conditions is examined and the heat input mechanism from indoor measurements investigated. This is important because high temperature decreases the open circuit voltage (Voc) of the cell/module which means less power output...

For the continued growth of PV capacity, it will be necessary to store vast amounts of energy to overcome seasonal differences in energy generation. To this end, the conversion of electricity to liquid or gas fuels could play an important role in the future energy system. There are numerous ways to create fuels from solar energy, the possibilities range from completely monolithically integrated photoelectrochemical (PEC) devices to configurations where the PV is completely decoupled from the electrochemical reaction. This thesis is part of the DISCO project, where the aim is to create multi-junction PV cells that can generate a high voltage and integrate these into PEC devices. The aim of this thesis project is to optimize the photovoltaic performance of a triple-junction device based on crystalline silicon (c-Si), nanocrystalline silicon (nc-Si:H) and amorphous silicon (a-Si:H). The bottom junction of this triple-junction device is a wafer-based silicon heterojunction (SHJ) cell. The used wafer should have a smooth surface texture, since previous research has shown that growing a nc-Si:H absorber layer on the regular random pyramid surface texture results in the formation of cracks. To this end, three different proposed smooth surface textures were compared amongst each other. These surface textures were a smooth pyramid surface texture, a hexagonal surface texture created with photolithography, and a texture of crater like surface features obtained by etching a sacrificial layer. It was found that from these three textures, the best performing SHJ cells could be made from wafers with a smooth pyramid surface texture. With respect to the other surface textures, the smooth pyramid surface texturing approach leads to the smallest fraction of exposed <100> crystal orientations, which are more challenging to passivate. The performance of the SHJ cell is extremely sensitive to the passivation quality of the intrinsic amorphous silicon layers on both side of the wafer. By optimizing this passivation layer and the doped layers, SHJ bottom cell efficiencies of over 18% were achieved. The middle junction of this triple-junction device is based on a nc-Si:H absorber layer. By varying the crystallinity of this i-nc-Si:H absorber layer, it was found that optimal photovoltaic performance is achieved for a crystalline volume fraction between 50% and 65%. Furthermore, the thickness of this absorber layer can be varied to improve the current matching between the different subcells in the triple-junction device. To this end, the effect of a varying absorber layer thickness on the single-junction PV performance was investigated. It was found that the absorber layer thickness is a trade-off between on the one hand Voc and FF, and on the other hand Jsc. For example, doubling the absorber layer thickness from 2.5 µm to 5.0 µm results in a Jsc increase from 18.2 mA/cm2 to 20.8 mA/cm2, whereas the Voc and the FF respectively decrease from 506 mV and 0.65 to 481 mV and 0.59. Once the bottom and middle junctions were optimized, different material combinations in the tunnel recombination junctions of the multi-junction device were investigated. It was found that p-nc-SiOx and n-nc-SiOx with appropriate doping levels and contact layers were the best performing materials in both tunnel recombination junctions. When the Voc of the tandem cells was compared to the sum of the single-junction cells, the optimized tunnel recombination junctions resulted in a Voc loss of 7 mV in the top tandem (nc-Si:H/a-Si:H), and 51 mV in the bottom tandem (SHJ/nc-Si:H). By making use of all the performed optimizations described above, a triple-junction device based on c-Si/nc-Si:H/a-Si:H was processed. The final device had a PV efficiency of 13.63%, with a FF of 0.755, a Voc of 1982 mV and a Jsc of 9.11 mA/cm2. To the best of our knowledge, this is a world-record efficiency for this type of solar cell configuration. If it is managed in future research to match the current over the different subcells more evenly, this device has the potential to achieve a current density over 12 mA/cm2.

Many functional photovoltaic (PV) modules are decommissioned prematurely, often due to the financially motivated repowering of PV systems. This study assesses under which circumstances there is an environmental incentive to reuse these modules as opposed to recycling and replacing them with new, more efficient modules. A life cycle assessment was conducted, covering the end-of-life treatment, manufacturing, transport and use phase of decommissioned and new modules. The decommissioned modules had an efficiency of 14.7% in 2011, the new modules have an efficiency of 19.79%. The analysis covers two different reuse scenarios (local and export) and two different replacement scenarios, based on the quality of the recycling and the manufacturing country of the new modules. The impacts are quantified in three categories: global warming potential, eco-cost of resource scarcity and total eco-cost. The findings indicate that, because of rapid technological advancements, the recycling and replacement of 10-year old decommissioned modules generally yield greater environmental benefits than local reuse: the net benefit in terms of global warming is greater after only 5 years. In addition, the calculations show that reusing decommissioned modules in a new PV system is only the preferred strategy from a global warming perspective if the modules are less than 5 years old, if that system is intended to have a (financial) lifetime of 10 years or longer. However, reuse in a selected European Union member state can provide greater benefits in the global warming potential and total eco-cost impact categories than recycling and replacement. The advantage of export is driven by higher annual irradiation as well as a higher emissions intensity of the electricity mix. These results contrast the conventional belief that reuse is always environmentally preferable to recycling. Based on this research it can be argued that in most cases of premature decommissioning, there is no strong environmental incentive to reuse the modules, provided that new PV modules are widely available or that the materials go directly to the production of new modules. The annual efficiency increase of PV technology was identified as a key parameter for this outcome.

Within the photovoltaic industry, a lot of research is done in order to minimize losses which are created during the conversion of solar light to electrical energy. In a crystalline silicon solar cell light has to pass through several layers before it enters the silicon wafer where the electron-hole pairs are generated. As one can imagine, if more light reaches the active layer, more electron-hole pairs can be generated. It is highly desired that only one layer, the active layer, is absorbing photons of the solar spectrum. The active layers at the sunny side of the silicon wafer should be highly transparent for solar light. In addition to being transparent, these layers should be conductive to extract the generated charge carriers to the metal contacts. Current layers applied at the sunny side are not optimally transparent, so it is still possible to increase the efficiencies in the crystalline silicon solar cells. In this study, doped silicon oxide layers have been explored as a potential more transparent layer for passivation of both the silicon surface and the metal contacts. Two routes for the fabrication of doped silicon oxide layers were investigated: post-oxidation of doped polycrystalline silicon layers and post-doping of in-situ grown silicon oxide layers. To characterize this new type of material, several different measurement techniques have been applied to improve our understanding of Low-Pressure Chemical Vapor Deposition deposited silicon oxide passivating contact layers. It was found that the structure and composition of the layers is very different for these different routes. However, very good and stable surface passivation (minority carrier lifetime of >3ms) can be achieved with both types of silicon oxide layers. Also, sheet resistance measurements have indicated that phosphorus doping in silicon oxides is possible. For better insight into the electrical properties of these layers, further testing in electronic test structures is advised.

Performance of photovoltaic modules are widely expressed using their efficiency at Standard Test Conditions (STC). Although, real world conditions largely differ from this standard. Energy yield of photovoltaic modules at a certain location gives a clear indication of the performance of the module exposed to varying weather conditions. Photovoltaic Materials and Devices (PVMD) Toolbox developed at Delft University of Technology and implemented in MATLAB®, aims to simulate energy yield of photovoltaic modules while providing the flexibility of modifying cell-level to module-level parameters of the device. Accurately determining the irradiance falling on the module at a certain location and simulating the electrical properties of a solar cell at realistic conditions is crucial in determining the yield generated by a module. Due to the promising results displayed by the technology, in this study, energy yield of perovskite/c-Si tandem modules are simulated using newly developed daylight and parameter extraction models in PVMD toolbox. Due to high computational efficiency and functionality offered, Preetham daylight model is implemented as an improvement to Perez model currently used in PVMD toolbox. The model considers the effect of Rayleigh and Mie scattering, and turbidity of atmosphere in determining the distribution of diffuse irradiance across the skydome. By implementing the model, three factors can now be determined: luminance distribution, RGB co-ordinates and relative spectral power distribution over the skydome for any location. Luminance is calculated for every point in sky using Perez parametric function that use coefficients derived from simulated data for different sun directions and turbidity values. For all locations considered, Preetham model calculates higher luminance over the year by ~2%. Calculated luminance values normalized against zenith luminance is used to derive CIE xyY values and consecutively, the RGB co-ordinates that are rendered real-time to create images of the skydome for every hour in chosen timeframe. By calculating the relative spectral power distribution, analysis of incident light falling on the module from all points of the skydome is possible which especially deems useful for modelling tandem modules. To accurately simulate electrical properties of solar cell under varying operating conditions, parameter extraction model for simulated ASA J-V curves is implemented using an analytical method. For the c-Si and perovskite cells considered in the study, the reconstructed curves using extracted parameters fits ASA curve with RMSE or 1.98% and 3.02% respectively at STC. Using these models introduced in this study, energy yield of mono-facial and bi-facial 2T/4T tandem modules are calculated and analyzed for Rome, Reykjavik and Alice Springs. Depending on air mass of a location, perovskite thickness of mono-facial 2T tandem devices are optimized to produce maximum specific yield. All considered modules generate highest yield at Alice Springs due to high insolation at the location. The yield difference between modules while using the two daylight models is insignificant at <1%. With an increase in perovskite thickness, energy yield of 2T bi-facial modules increase significantly for high albedo while it drops beyond the optimum thickness due to current mismatch for low albedo. Bi-facial 4T module on high albedo (albedo= 0.85) surfaces show best performance out of all the modules producing 36% higher yield than mono-facial 4T module for Rome.

In order to make the bifacial yield prediction models commercially available, a lot of work their development, improvement and validation is being done by many research institutes. At Energy research center of the Netherlands (ECN), one such model is under development. In this project, couple of aspects were investigated to give better insight into improving the model. The two main aspects of the model that were investigated were the rear irradiance estimation and the temperature prediction of the model. Analysis of rear irradiance aspect of the bifacial yield model through simulations at low tilt angles and elevations should in practice result low rear irradiance but the results showed the opposite. From the literature, a new factor called acceptance was implemented in the rear irradiance model which led to correction in estimation of rear irradiance. For the temperature model, initially indoor measurements of three laminates of bifacial cells and three laminates of monofacial cells were performed under solar simulator. The experiment resulted in finding differences in measured and cell temperatures for all six laminates. According to measured temperatures, the bifacial cell laminates were hotter than their monofacial counterparts, which may not be correct due to higher absorption of irradiance by backsheets in bifacial cell laminates. The differences in calculated cell temperature and measured temperature were investigated and were found to be different. The heating behavior of all laminates was modelled and heat capacity and heat transfer coefficient found through modelling were found to be in good agreement with literature values. Outdoor measurements were used for temperature analysis of bifacial panels and again the differences in calculated cell temperature and measured temperature were found. Non-steady state temperature model was found to be more accurate for low resolution meteorological and insolation data of less than ten minutes as compared to the steady state model used by current ECN model. The difference between measured and cell temperature was translated in terms of heat transfer coefficient and for this difference, the annual energy yield results showed a variation of 1.45 %. The results of the project showed improvement of the bifacial yield model by ECN through an improved rear irradiance estimation. Furthermore, non-steady model should be used in case the input meteorological and insolation data is in less than ten-minute interval.

With the fast expanding photovoltaic (PV) industry, we are currently witnessing an unprecedented evolution of high-efficiency PV technologies in laboratories. The topic of this thesis is certainly among the novel technologies that could eventually break through on the market. Ultra-thin molybdenum oxide (MoOx) layer, as a hole-selective contact in a silicon heterojunction (SHJ) solar cell, was found to be suitable due to its transparency and high work function. This work presents the implementation of a MoOx layer in a 6 inch SHJ solar cell piloting towards an industrial level. Moreover, with MoOx commonly thermally deposited, this report shows the applicability of the electron beam evaporator for large scale deposition.