Olivier Palais

Bio: Olivier Palais is an academic researcher from Aix-Marseille University. The author has contributed to research in topics: Silicon & Carrier lifetime. The author has an hindex of 12, co-authored 74 publications receiving 624 citations. Previous affiliations of Olivier Palais include Université Paul Cézanne Aix-Marseille III.

Silicon-rich SiO2/SiO2 multilayers: A promising material for the third generation of solar cell

Abstract: Si-rich-SiO 2 SRSO / SiO 2 multilayers MLs have been grown by reactive magnetron sputtering. The presence of silicon nanoclusters Si-ncls within the SRSO sublayer and annealing temperature influence optical absorption as well as photoluminescence. The optimized annealing temperature has been found to be 1100 ° C, which allows the recovery of defects and thus enhances photoluminescence. Four MLs with Si-ncl size ranging from 1.5 to 8 nm have been annealed using the optimized conditions and then studied by transmission measurements. Optical absorption has been modeled so that a size effect in the linear absorption coefficient in cm −1 has been evidenced and correlated with TEM observations. It is demonstrated that amorphous Si-ncl absorption is fourfold higher than that of crystalline Si-ncls.

Influence of iron contamination on the performances of single-crystalline silicon solar cells: Computed and experimental results

Abstract: In this paper, the impact of iron contamination on the conversion efficiency of single-crystalline p-type silicon solar cells is investigated by means of the combination of numerical simulations and experimental data, taking into account the more recent results about the properties of iron in single-crystalline silicon. Numerical simulations highlight the fill factor losses due to the injection-level dependence of the bulk lifetime, which attenuates the decrease of the open circuit voltage and thus that of the solar cell conversion efficiency with iron concentration. Gettering and hydrogenation effects are quantified by means of experimental results obtained from voluntarily contaminated solar cells and integrated in the simulations. The results show that iron appears to be a metallic impurity rather well tolerated in p-type single-crystalline silicon solar cells, because its injection-level dependent bulk lifetime, like its abilities to be gettered and to be passivated by hydrogenation, limits its influe...

Effect of intentional bulk contamination with iron on multicrystalline silicon solar cell properties

Abstract: The influence of intentional iron bulk contamination on the performances of boron doped p-type multicrystalline silicon solar cells was investigated. Solar cells were made from iron contaminated wafers, with an initial dissolved iron concentration 100 times higher than that of standard wafers. Nevertheless, the conversion efficiency of these cells was not impacted by this intentional contamination. We showed that this tolerance toward iron was due to the efficiency of the gettering and hydrogenation effects, complementary in this material. While phosphorus diffusion (extracting more than 99% of the iron from the bulk) is slightly limited in regions of high dislocation density, hydrogen diffuses through the whole thickness of the wafer and passivates defects and remaining impurities, with its diffusion being faster along extended defects

Effect of total pressure on the formation and size evolution of silicon quantum dots in silicon nitride films

Abstract: The size of silicon quantum dots (Si QDs) embedded in silicon nitride (SiN(x)) has been controlled by varying the total pressure in the plasma-enhanced chemical vapor deposition (PECVD) reactor. This is evidenced by transmission electron microscopy and results in a shift in the light emission peak of the quantum dots. We show that the luminescence in our structures is attributed to the quantum confinement effect. These findings give a strong indication that the quality (density and size distribution) of Si QDs can be improved by optimizing the deposition parameters which opens a route to the fabrication of an all-Si tandem solar cell.

A Comprehensive Review of Semiconductor Ultraviolet Photodetectors: From Thin Film to One-Dimensional Nanostructures

Abstract: Ultraviolet (UV) photodetectors have drawn extensive attention owing to their applications in industrial, environmental and even biological fields. Compared to UV-enhanced Si photodetectors, a new generation of wide bandgap semiconductors, such as (Al, In) GaN, diamond, and SiC, have the advantages of high responsivity, high thermal stability, robust radiation hardness and high response speed. On the other hand, one-dimensional (1D) nanostructure semiconductors with a wide bandgap, such as β-Ga2O3, GaN, ZnO, or other metal-oxide nanostructures, also show their potential for high-efficiency UV photodetection. In some cases such as flame detection, high-temperature thermally stable detectors with high performance are required. This article provides a comprehensive review on the state-of-the-art research activities in the UV photodetection field, including not only semiconductor thin films, but also 1D nanostructured materials, which are attracting more and more attention in the detection field. A special focus is given on the thermal stability of the developed devices, which is one of the key characteristics for the real applications.

Materials Science Forum

Abstract: Properties and Application of Geopolymers Vol. 841 (/MSF.841 /book) Development and Investigation of Materials Using Modern Techniques Vol. 840 (/MSF.840/book) Superplasticity in Advanced Materials ICSAM 2015 Vols. 838-839 (/MSF.838-839/book) 12th International Conference on High Speed Machining Vols. 836-837 (/MSF.836-837/book) Sintering Fundamentals II Vol. 835 (/MSF.835/book) Advanced Machining Technologies: Traditions and Innovations Vol. 834 (/MSF.834/book) Applied Materials and Technologies Vol. 833 (/MSF.833/book) Emerging Functional Materials: Book (/MSF.841/book) Papers (/MSF.841)

Dielectric surface passivation for silicon solar cells: A review

Abstract: Silicon wafer solar cells continue to be the leading photovoltaic technology, and in many places are now providing a substantial portion of electricity generation. Further adoption of this technology will require processing that minimises losses in device performance. A fundamental mechanism for efficiency loss is the recombination of photo-generated charge carriers at the unavoidable cell surfaces. Dielectric coatings have been shown to largely prevent these losses through a combination of different passivation mechanisms. This review aims to provide an overview of the dielectric passivation coatings developed in the past two decades using a standardised methodology to characterise the metrics of surface recombination across all techniques and materials. The efficacy of a large set of materials and methods has been evaluated using such metrics and a discussion on the current state and prospects for further surface passivation improvements is provided.

Surface-passivated GaAsP single-nanowire solar cells exceeding 10% efficiency grown on silicon.

Abstract: The use of III-V semiconductor nanowires can overcome the need for lattice matching in multi-junction solar cells, which restricts the choice of materials and their bandgaps. This work demonstrates efficient solar cells with GaAsP single nanowires with tunable bandgap and grown on low-cost Si substrates.