A5040236350- Silicon and Solar Cell Technologies
- Thin-Film Transistor Technologies
- Silicon Nanostructures and Photoluminescence
- Photovoltaic System Optimization Techniques
- Semiconductor materials and interfaces
- Photovoltaic Systems and Sustainability
- Advanced Surface Polishing Techniques
- solar cell performance optimization
- Microstructure and mechanical properties
- Nanowire Synthesis and Applications
- Solidification and crystal growth phenomena
- Solar Thermal and Photovoltaic Systems
- Metal Forming Simulation Techniques
- Semiconductor materials and devices
- Metallurgy and Material Forming
- Solar Radiation and Photovoltaics
- Integrated Circuits and Semiconductor Failure Analysis
Hamad bin Khalifa University
2016-2024
Qatar Foundation
2015-2021
Massachusetts Institute of Technology
2013-2017
Norwegian University of Science and Technology
2011-2012
In this paper, we report the evolution of silicon heterojunction solar cell properties focusing, in particular, on indium tin oxide (ITO) layers upon consecutive thermal annealing. We find that charge carrier density N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e</sub> ITO increases with higher budget, while mobility remains constant. For cells, their series resistance at maximum power point R...
Performance and reliability of photovoltaic (PV) systems are important for the deployment PV in desert climate. In this study, we investigate performance multi-crystalline, mono-crystalline silicon heterojunction arrays operating field 5-years from 2014 to 2018 under From data monitoring performing visual inspection at field, a drop energy yield presence various defects were observed therefore further in-depth analysis was required identify potential main cause losses. For (Multi_D),...
The performance and reliability of photovoltaic (PV) modules in a desert climate depends, among other factors, on the solar irradiance, operating temperature, soiling rate. Since impacts these environmental factors depend type PV module technology, an assessment technology to be deployed is crucial for bankability projects. In this work, indoor outdoor monofacial bifacial silicon heterojunction technologies were assessed. For measurements, comparison current-voltage (IV) characteristics was...
The noncontact crucible method enables production of Si bulk single crystals without contact by intentionally establishing a distinct low-temperature region in the melt. In this contribution, we correlate crystal growth conditions to material properties. shape growing interface was generally convex direction. quality ingots determined spatial distributions dislocations, resistivity, oxygen concentration, and minority-carrier lifetime. an ingot with bottom, swirl patterns higher resistivity...
The microstructure of commonly occurring dislocation patterns in industrial directionally solidified multicrystalline silicon has been systematically studied by light microscopy, electron backscatter diffraction, and transmission microscopy. work focused on clusters wafers near the top cast blocks. In {111} grain surface, arrays parallel to {110} plane traces are lying rows planes inclined mainly 〈112〉30∘ orientation. configuration suggests that may result from a recovery process....
Dislocation clusters in multicrystalline silicon limit solar cell performance by decreasing minority carrier diffusion length. Studies have shown that the recombination strength of dislocation can vary up to two orders magnitude, even within same wafer. In this contribution, we combine a surface-analysis approach with bulk characterization techniques explore underlying root cause variations among different clusters. We observe higher consist dislocations larger variation line vector,...
The microstructure of highly dislocated stacking fault regions (dislocation density &gt;106 cm−2) in industrial cast multicrystalline silicon has been investigated by light microscopy, scanning electron and transmission microscopy. Our observations indicate that faults form strong barriers to lattice dislocation movement the formation sub grain boundaries. Stepped curved edges appear generate dislocations. suggest play an important role plasticity as well dislocations silicon.
The Photovoltaic (PV) market is dominated by crystalline silicon materials in the form of high-quality high-cost Czochralski monocrystalline (mono-Si) and lower-cost defect-prone crucible-cast multicrystalline (mc-Si). Therefore, development commercialization offering high efficiency cells at low cost necessary for wider deployment photovoltaic systems. Several alternative crystallization techniques aimed lowering material-cost improving energy conversion are being developed. These include...
We report independently confirmed 22.15% and record 22.58% power conversion efficiencies for thin (130–140 μm) p-type n-type monolike Si solar cells, respectively. comparatively assessed advanced silicon wafers potential use in low-cost, high-efficiency cell applications by using phosphorus diffusion gettering material-quality improvement heterojunction fabrication assessment of performance photovoltaic device architecture. show that improves material quality properties significantly,...
Desert environments exhibit high soiling rates that have a profound impact on the energy yield and operations maintenance of Photovoltaic (PV) power plants. This study investigates vertical east–west (Vertical) installation bifacial PV modules in desert climates − its effectiveness generation as mitigation strategy for soiling. To assess module bifaciality orientation soiling, we compared performance latitude-tilted, i.e. 22° facing South (Tilted) monofacial, under real outdoor climatic...
A crystal is known to achieve lower energy if lattice dislocations are re-arranged in arrays forming a sub-grain boundary through recovery process. Interaction of with glide also expected bring about local equilibrium. In this work, localised the vicinity (mis-orientation ) studied detail by transmission electron microscopy order determine their source. Contrary processes described above, it appears that source these dislocations, which emitted from some locally stressed parts boundary....
Today, solar cells are generally optimized for 25 °C, whereas in most climates, especially hot and sunny ones, the operating device temperature is usually much higher, e.g. range of 60 °C. We investigate use n-doped nanocrystalline silicon oxide layers (nc-SiOx:H(n)) as front contact stacks heterojunction compare them with oxide-free contacts. Whereas a short-circuit current density 41 mAcm−2 could be obtained due to increased transparency nc-SiOx:H(n) layers, fill-factor drastically reduced...
The presence of metal impurities and their interactions with structural defects (e.g., dislocations) are deleterious to the performance Si-based solar cell devices. To achieve higher minority carrier lifetimes that translate into efficiencies, novel growth methods low dislocation densities reduced impurity concentrations have recently been developed. These simultaneously aim capital expense (capex), necessary ensure rapid industry scaling. Monocrystalline Si grown by non-contact crucible...
We have investigated the source of dislocations generated during growth and subsequent cooling quasi‐monocrystalline silicon. Bi‐crystals silicon separated by ∼5.2° tilt small angle grain boundary been directionally solidified at two different pulling rates, i.e., 3 13 μm s −1 . observe higher density boundary‐associated ingot pulled a lower rate. This observation is explained impact oxygen precipitation behavior boundary.
Light microscopy, electron backscatter diffraction and transmission microscopy is employed to investigate dislocation structure impurity precipitation in commonly occurring clusters as observed on defect-etched directionally solidified multicrystalline silicon wafers. The investigation shows that poligonised structures consist of parallel mostly similar, straight, well-ordered dislocations, with minimal contact-interaction no evidence precipitate decoration. On the other hand, disordered...
We report on the performance of Silicon Heterojunction (SHJ) solar cell under high operating temperature and varying irradiance conditions typical to desert environment. In order define best configuration that resist conditions, two different intrinsic passivation layers were tested, namely, an amorphous silicon a-SiOx:H with CO2/SiH4 ratio 0.4 0.8, obtained compared those a standard SHJ having a-Si:H layer. Our results showed how short circuit current density Jsc, fill factor FF...
Amorphous/crystalline silicon heterojunction (SHJ) solar cells technology is attracting tremendous attention in recent years due to its potential achieve high power conversion efficiencies at low fabrication temperatures and using few process steps. However, the commercial mass production of this still somehow restricted so far, which mainly sensitivity SHJ cell parameters growth conditions. A significant distinctness between configuration standard wafer current collection scheme. Indeed, as...
We applied hydrogen passivation, gettering and a combination of both to quasi-mono (qm) wafer material enhance its bulk lifetime prepared silicon heterojunction (SHJ) solar cells. find that while our passivation alone seems not lifetime, treatment increases so efficiencies up 21.5% were achieved with SHJ cell. This is close the highest efficiency reported for such variation absorber thickness plays minor role investigated cells similar could have been obtained Cz gettered qm wafers. The...