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Julie Dreon

Bio: Julie Dreon is an academic researcher from École Polytechnique Fédérale de Lausanne. The author has contributed to research in topics: Solar cell & Silicon. The author has an hindex of 5, co-authored 13 publications receiving 144 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the influence of the MoOx and intrinsic a-Si:H thicknesses on current-voltage properties and discuss transport and performance-loss mechanisms is discussed. But the authors focus on the front-side hole-selective layer.

163 citations

Journal ArticleDOI
TL;DR: In this paper, Vincent Paratte and Christophe Allebe from CSEM were employed for amorphous silicon preparation and high-quality wet-processing and metallization, respectively, and this project received funding from the European Union's Horizon 2020 research and innovation program under Grant Agreement No. 727523 (NextBase).
Abstract: The authors thank Vincent Paratte for amorphous silicon preparation and Christophe Allebe and Nicolas Badel from CSEM for the high-quality wet-processing and metallization. This project received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 727523 (NextBase), as well as Swiss national science foundation under Ambizione Energy grant ICONS (PZENP2_173627) and the China Postdoctoral Science Foundation (15Z102060052 and 16Z102060054). Part of this research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under award no. OSR-CRG URF/1/3383, as well as funding from Saudi Aramco.

51 citations

Journal ArticleDOI
01 Apr 2018
TL;DR: In this article, the authors would like to thank Raphael Monnard and Guillaume Charitat from EPFL and Nicolas Badel, Silvia Martin de Nicolas and Fabien Debrot from CSEM for work performed in the context of this publication.
Abstract: The authors would like to thank Raphael Monnard and Guillaume Charitat from EPFL and Nicolas Badel, Silvia Martin de Nicolas and Fabien Debrot from CSEM for work performed in the context of this publication. Furthermore, we thank Davide Sacchetto and Sylvain Nicolay from CSEM, and Andres Cuevas from ANU for discussions, Virginia Unkefer from KAUST for manuscript editing. S. Essig held a Marie Sklodowska-Curie Individual Fellowship from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No: 706744, action acronym: COLIBRI). Part of this work was funded by the European Union's Horizon 2020 research and innovation programme under Grant Agreements no. 727529 (project DISC), and by the Swiss National Science Foundation via the NRP70 “Energy Turnaround” project “PV2050.”

43 citations

Journal ArticleDOI
TL;DR: In this paper , the authors present a review of metal-compound-based selective contacts in the context of crystalline silicon photovoltaics, focusing on the potential benefits in terms of performance, cost, ease of processing or stability.
Abstract: Solar cells rely on the efficient generation of electrons and holes and the subsequent collection of these photoexcited charge carriers at spatially separated electrodes. High wafer quality is now commonplace for crystalline silicon (c‐Si) based solar cells, meaning that the cell's efficiency potential is largely dictated by the effectiveness of its carrier‐selective contacts. The majority of contacts currently employed in industrial production are based on highly doped‐silicon, which can introduce negative side‐effects including Auger recombination or parasitic absorption depending on whether the dopants are diffused into the absorber or whether they are incorporated into silicon layers deposited outside the absorber. Given the terawatt scale of deployment of c‐Si solar cells, the search for alternative contacting schemes that can offer potential benefits in terms of performance, cost, ease of processing or stability is highly relevant. One such category of contacting schemes, with the potential to avoid the above mentioned issues, is that which employs metal compounds as the ‘carrier‐selective’ layer. The last 7 years has seen a surge in interest on this topic and a few promising families of materials have emerged, most prominently the alkali/alkaline‐earth metal compounds and the transition‐metal oxides. The number of successful selective‐contact demonstrations of materials within these families is fast increasing with the best solar cell demonstrations now exceeding 23%. However, in addition to improving their efficiency performance, several challenges remain if such contacts are to be considered for industrial adoption. These are mainly associated with poor stability, lack of compatibility with transparent electrodes and inability to be deposited using standard industrial techniques. This review covers the historical developments, current status and future prospects of metal‐compound based selective contacts in the context of c‐Si photovoltaics.

19 citations

Journal ArticleDOI
09 Nov 2020
TL;DR: In this article, the authors proposed a method for depositing diopant-free contacts for photovoltaics with the potential to be deposited at low costs while providing excellent surface passivation and low contact resistance.
Abstract: Dopant-free passivating contacts for photovoltaics have the potential to be deposited at low costs while providing excellent surface passivation and low contact resistance. However, one pressing is...

16 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the influence of the MoOx and intrinsic a-Si:H thicknesses on current-voltage properties and discuss transport and performance-loss mechanisms is discussed. But the authors focus on the front-side hole-selective layer.

163 citations

Journal ArticleDOI
TL;DR: In this article, a high performance, low-temperature, electron-selective heterocontact is developed, comprised of a surface passivating a-Si:H layer, a protective TiOx interlayer, and a low work function LiFx/Al outer electrode.
Abstract: Development of new device architectures and process technologies is of tremendous interest in crystalline silicon (c-Si) photovoltaics to drive enhanced performance and/or reduced processing cost. In this regard, an emerging concept with a high-efficiency potential is to employ low/high work function metal compounds or organic materials to form asymmetric electron and hole heterocontacts. This Letter demonstrates two important milestones in advancing this burgeoning concept. First, a high-performance, low-temperature, electron-selective heterocontact is developed, comprised of a surface passivating a-Si:H layer, a protective TiOx interlayer, and a low work function LiFx/Al outer electrode. This is combined with a MoOx hole-selective heterocontact to demonstrate a cell efficiency of 20.7%, the highest value for this cell class to date. Second, we show that this cell passes a standard stability test by maintaining >95% of its original performance after 1000 h of unencapsulated damp heat exposure, indicating...

154 citations

Journal ArticleDOI
TL;DR: In this paper, the development status of high-efficiency crystalline silicon (c-Si) heterojunction solar cells, from the materials to devices, mainly including hydrogenated amorphous silicon (a-Si:H) based silicon heterjunction technology, polycrystalline silicon based carrier selective passivating contact technology, metal compounds and organic materials based dopant-free contact technology are reviewed.
Abstract: Photovoltaic (PV) technology offers an economic and sustainable solution to the challenge of increasing energy demand in times of global warming. The world PV market is currently dominated by the homo-junction crystalline silicon (c-Si) PV technology based on high temperature diffused p-n junctions, featuring a low power conversion efficiency (PCE). Recent years have seen the successful development of Si heterojunction technologies, boosting the PCE of c-Si solar cells over 26%. This article reviews the development status of high-efficiency c-Si heterojunction solar cells, from the materials to devices, mainly including hydrogenated amorphous silicon (a-Si:H) based silicon heterojunction technology, polycrystalline silicon (poly-Si) based carrier selective passivating contact technology, metal compounds and organic materials based dopant-free passivating contact technology. The application of silicon heterojunction solar cells for ultra-high efficiency perovskite/c-Si and III-V/c-Si tandem devices is also reviewed. In the last, the perspective, challenge and potential solutions of silicon heterojunction solar cells, as well as the tandem solar cells are discussed.

112 citations

Journal ArticleDOI
TL;DR: In this paper , the authors survey the key changes related to materials and industrial processing of silicon PV components and discuss what it will take for other PV technologies to compete with silicon on the mass market.
Abstract: Crystalline silicon (c-Si) photovoltaics has long been considered energy intensive and costly. Over the past decades, spectacular improvements along the manufacturing chain have made c-Si a low-cost source of electricity that can no longer be ignored. Over 125 GW of c-Si modules have been installed in 2020, 95% of the overall photovoltaic (PV) market, and over 700 GW has been cumulatively installed. There are some strong indications that c-Si photovoltaics could become the most important world electricity source by 2040–2050. In this Review, we survey the key changes related to materials and industrial processing of silicon PV components. At the wafer level, a strong reduction in polysilicon cost and the general implementation of diamond wire sawing has reduced the cost of monocrystalline wafers. In parallel, the concentration of impurities and electronic defects in the various types of wafers has been reduced, allowing for high efficiency in industrial devices. Improved cleanliness in production lines, increased tool automation and improved production technology and cell architectures all helped to increase the efficiency of mainstream modules. Efficiency gains at the cell level were accompanied by an increase in wafer size and by the introduction of advanced assembly techniques. These improvements have allowed a reduction of cell-to-module efficiency losses and will accelerate the yearly efficiency gain of mainstream modules. To conclude, we discuss what it will take for other PV technologies to compete with silicon on the mass market. Crystalline silicon solar cells are today’s main photovoltaic technology, enabling the production of electricity with minimal carbon emissions and at an unprecedented low cost. This Review discusses the recent evolution of this technology, the present status of research and industrial development, and the near-future perspectives.

67 citations

Journal ArticleDOI
TL;DR: Kohler et al. as mentioned in this paper proposed a passivating contact based on a double layer of nanocrystalline silicon carbide that overcomes the trade-offs of conductivity, defect passivation and optical transparency.
Abstract: A highly transparent passivating contact (TPC) as front contact for crystalline silicon (c-Si) solar cells could in principle combine high conductivity, excellent surface passivation and high optical transparency. However, the simultaneous optimization of these features remains challenging. Here, we present a TPC consisting of a silicon-oxide tunnel layer followed by two layers of hydrogenated nanocrystalline silicon carbide (nc-SiC:H(n)) deposited at different temperatures and a sputtered indium tin oxide (ITO) layer (c-Si(n)/SiO2/nc-SiC:H(n)/ITO). While the wide band gap of nc-SiC:H(n) ensures high optical transparency, the double layer design enables good passivation and high conductivity translating into an improved short-circuit current density (40.87 mA cm−2), fill factor (80.9%) and efficiency of 23.99 ± 0.29% (certified). Additionally, this contact avoids the need for additional hydrogenation or high-temperature postdeposition annealing steps. We investigate the passivation mechanism and working principle of the TPC and provide a loss analysis based on numerical simulations outlining pathways towards conversion efficiencies of 26%. Passivating contacts hold promise for silicon solar cells yet the simultaneous optimization of conductivity, defect passivation and optical transparency remains challenging. Now Kohler et al. devise a passivating contact based on a double layer of nanocrystalline silicon carbide that overcomes these trade-offs.

65 citations