News

© 2024 EPFL

Organic spacers create free charges in layered halide Perovskites

— The LIMNO lab introduces a new lead-halide-based Ruddlesden–Popper perovskite structure based on a visible-light-absorbing naphthalene-iminoimide cation. The optoelectronic properties of this new material represent an important step toward enhancing light harvesting and affording the spatial separation of charge carrier transport in stable layered perovskite-based devices.

© 2020 EPFL

Rebekah Wells receives the 2024 Lopez-Loreta Prize

— After defending her PhD in 2022, Rebekah Wells launches her research program on chiral 2D nanomaterials, thanks to the 1M Euros support of the Lopez-Loreta Foundation.

© 2024 LIMNO/EPFL

New insights into Charge Carrier Dynamics for Solar Fuels

— Combining photoelectrochemical impedance spectroscopy with in-situ UV–vis spectroscopy, a new LIMNO report evaluates the charge carrier dynamics of organic semiconducting photoanodes for solar fuel applications. Combining photoelectrochemical impedance spectroscopy with in-situ UV–vis spectroscopy, a new LIMNO report evaluates the charge carrier dynamics of organic semiconducting photoanodes for solar fuel applications.

© 2024 EPFL/P. Ferdowsi

β-Cyclodextrin in Controlling Perovskite Solar Cell Performance

— Supramolecular interactions are demonstrated to be key to enhancing performance and stability of triple cation perovskite solar cells.

© 2024 EPFL

Interfacial engineering using crown ethers in perovskite solar cells

— Interfacial engineering through lead binding (crown ethers) achieves lead ion sequestration and robust interfacial passivation, enhancing stability and efficiency of perovskite solar cells.

© 2024 EPFL/R. Wells

LIMNO develops scalable method for alloyed 2D material production

— Continuously tuneable optoelectronic properties from alloyed two-dimensional (2D) transition metal dichalcogenides (TMDs) can now be attained simply on a large scale.

© 2023 LIMNO/EPFL

Recent Graduations at LIMNO

— Dr. Simon Nussbaum and Dr. YeonJu Kim receive their PhD degrees from EPFL!

© 2023 LIMNO/EPFL

Organic-Inorganic Semiconductors Demonstrate Enhanced Charge Transfer

— EPFL scientists have made significant progress in the development of hybrid layered organic-inorganic perovskite semiconductors by incorporating novel spacer cations, according to a recent scientific paper published in the journal Chem. Sci. This advance gives promise to addressing the strong dielectric and quantum confinement effects typically encountered in layered perovskite materials, allowing for improved charge-transfer capabilities.

© 2023 The authors/EPFL

Photoelectrochemical CO2 Reduction Directly on CIGS Surface

— LIMNO researchers have demonstrated that photoelectrochemical CO2 reduction occurs with high selectivity at a direct CuInGaS2/electrolyte junction when the electrolyte conditions are correctly tuned. 

© N. Plainpan 2023 EPFL

Nukorn Plainpan defends his PhD thesis

— Dr. Nukorn Plainpan received the degree of Docteur ès Sciences after successfully defending his thesis entitled "Tungsten oxide-based photoanodes: biomass valorization and the effects of oxygen vacancies." Congratulations Dr. Nukorn !

© 2023 EPFL / Alain Herzog

A step towards solar fuels out of thin air

— EPFL chemical engineers have invented a solar-powered artificial leaf, built on a novel electrode which is transparent and porous, capable of harvesting water from the air for conversion into hydrogen fuel. The semiconductor-based technology is scalable and easy to prepare.

© 2022 EPFL

Doctoral Thesis Award Chemistry & Chemical Engineering (ISIC) 2022.

— Congratulations to the Winners : Dr Rebekah Wells (Winner) Dr Elena Braconi (Runner-up)

© 2022 EPFL

An Organic Semiconductor PEC Tandem Cell for Solar Water Splitting

— LIMNO reports major advance in the photoelectrochemical (PEC) splitting of water into H2 and O2 using organic semiconductors.

© K. SIVULA / EPFL 2022

Derivative voltammetry: a simple tool to probe reaction selectivity

— LIMNO has reported a a simple tool to probe reaction selectivity in photoelectrochemical cells for light-driven H2 production and biomass reformation 

K.Sivula with Dr. Barbara Primera Darwich (left), Dr. Marina Caretti (middle) and Dr. Rebekah Wells (right)  © K.SIVULA / 2022 EPFL

Recent PhD graduations at LIMNO !

— LIMNO is proud to congratulate Dr. Barbara Primera Darwich, Dr. Marina Caretti, and Dr. Rebekah Wells, who all recently passed their PhD defenses !

© MRS 2022

Rebekah Wells wins Graduate Student Award!

— At the 2022 MRS (Materials Research Society) Spring Meeting, Rebekah Wells won the Gold Graduate Student Award! 

© 2022 LIMNO/EPFL

LIMNO discovers new copper oxide deposition method

— The in situ electro-conversion of an electrodeposited CuSCN film into Cu2O is reported to produce photocathodes with improved performance for solar hydrogen production.

© LIMNO 2022 EPFL

LIMNO develops a route for making 2D nanosheets with fewer defects

— Semiconducting 2D transition metal dichalogenide (2D-TMD) nanosheets are promising materials for ultrathin optoelectronic devices, but most scalable routes lead to defective nanosheets and disappointing performance. Now, in a new article, Rebekah Wells of the LIMNO lab and her colleagues have presented a new solution processable method which uses an electrochemical pellet intercalation (ECPI) technique to make high quality nanosheets with fewer defects and higher quantum efficiencies.

© LIMNO 2022 EPFL

Dr. Arvindh Sekar defends his thesis !

— Dr. Arvindh Sekar has obtained the degree of docteur ès sciences from the EPFL for his thesis entitled "Organic Semiconductors for Photoelectrochemical Applications" Congratulations Dr. Sekar! 

© 2022 EPFL

Insights towards optimizing electron injection in BHJ photoanodes

— The use of a bulk heterojunction (BHJ) of organic semiconductors to drive solar-to-fuel energy con version via photoelectrochemical water splitting is an emerging trend; however, the optimum energy levels of the donor and acceptor have not been established for photoanode operation with respect to electrolyte pH. Now in a new paper, Dr. Arvindh Sekar of the LIMNO lab at EPFL has revealed important factors that determine efficient electron injection.

© 2021 / N. Guijarro EPFL

Identifying Reactive Sites & Surface Traps in Solar Fuel production

— The LIMNO and LPI laboratories in ISIC team up with UniBe to gain new insights into the operation of CuIn0.3Ga0.7S2 photocathodes for photoelectrochemical hydrogen production

© 2021 LIMNO EPFL

Dr. Yongpeng Liu defends his thesis !

— Dr. Yongpeng Liu has obtained the degree of docteur ès sciences from the EPFL for his thesis entitled "Novel Interfacial Characterization and Surface Engineering in Semiconductor Electrodes for Optimized Solar Fuel Production" Congratulations Dr. Liu ! 

© B. Primera Darwich / 2021 EPFL

Benzodithiophene‐Based Spacers for Layered Perovskites

— LIMNO researchers demonstrate the incorporation of a benzodithiophene (BDT)-based organic cation in layered and quasi-layered lead halide perovskites.

© 2021 LIMNO/EPFL

Solar-driven water oxidation with semiconducting polymers

— Scientists in LIMNO are generating oxygen from sunlight, water and semiconducting polymers with breakthrough performance. The approach presents a promising way towards economical and scalable solar fuel production.

© L.Yao / 2021 EPFL

A new “hybrid” approach for artificial photosynthesis

— ISIC scientists report a hybrid bulk-heterojunction photoanode with benchmark performance for direct solar-to-chemical conversion

© N. Guijarro / 2021 EPFL

LIMNO reports surface passivation of ZFO photoanodes

— Spectroelectrochemical and Chemical Evidence of Surface Passivation is presented for Zinc Ferrite (ZnFe2O4) Photoanodes for Solar Water Oxidation.

© K.Sivula/2020 EPFL

Towards cheaper hydrogen production via alkaline water splitting

— The ISIC laboratories of LIMNO and LMRE team up to uncover the influence of composition on performance in metallic Iron-Nickel-Cobalt ternary anodes for alkaline water electrolysis. 

© K.Sivula / 2020 EPFL

Dr. Nestor Guijarro receives ERC starting grant !

— For his project “RELICS” (Refining lignin by advanced catalytic schemes powered by Sunlight), Dr. Guijarro, who just finished his Ambizione Energy project in LIMNO at EPFL and is now affiliated with the University of Alicante, won the prestigious ERC starting grant. Congratulations Nestor!

© Y. Liu /2020 EPFL

Yongpeng Liu receives poster presentation award

— At the virtually attended Swiss Chemical Society (SCS) Fall Meeting 2020, LIMNO PhD student Yongpeng Liu received the Runner-up prize in Catalysis Sciences & Engineering.

© 2020 EPFL

Rebekah Wells of LIMNO wins Chemistry Travel Award

— The award is given yearly from SCNAT – the Swiss Academy of Sciences

©  C. Lhermitte /  2020 EPFL

New synthesis method for ternary metal oxide photoelectrodes

— Dr. Charles Lhermitte et al. of the LIMNO lab report the development of a mild but versatile method for thin-film synthesis as a “Very Important Paper” in ChemSUSChem.

© K. Sivula / EPFL 2020

Advancing artificial photosynthesis with organic semiconductors

— The LIMNO lab at EPFL reports a breakthrough in the performance and stability of organic pi-conjugated polymer semiconductors for photoelectrochemical solar hydrogen production

© K. Sivula / 2019 EPFL

Enabling the practical application of 2D semiconductors

— The LIMNO lab develops a method for the roll-to-roll processing of 2D nano-flake semiconductors into large-area photoactive thin film devices. 

© N. Guijarro / 2019 EPFL

LIMNO scientists demonstrate new type of hybrid solar cell

— Dr. Guijarro and Dr. Yao present the first demonstration of integrating CsPbI3 quantum dots into a conventional organic solar cell. The resulting performance enhancement has been published in Angewandte Chemie.

© Y. Liu / 2019 EPFL

LIMNO PhD student wins poster prize at SCS photochem meeting

— On June 14, at the Swiss Chemical Society (SCS) Photochemistry Symposium 2019 in HEIA Fribourg, LIMNO PhD student Yongpeng Liu won 2nd place Poster prize. 

© 2019 EPFL/K.Sivula

Alternative Oxidation Reactions for Solar-Driven Fuel Production

— A new perspective on how to valorize oxidation reactions during the artificial photosynthesis of solar fuel is reported by LIMNO researchers in the journal ACS Catalysis. 

© 2019 EPFL/K.Sivula

Y. Liu and N. Guijarro shine new light on copper ferrite photoanodes

— Photoelectrochemical solar fuel production requires robust photoanode materials. In a new report published in the Journal of Materials Chemistry A, Yongpeng Liu and Dr. Néstor Guijarro lead a study that reveals deep insights into the performance of a potential photoanode material:Copper ferrite.

© 2019 EPFL/K.Sivula

LIMNO Reports New Route to Make Stable Organic Solar Cells

— The stability of donor-acceptor bulk heterojunction organic photovoltaics (BHJ OPV) can be increased by using fully conjugated block co-polymers (BCPs) but the lack of facile routes to prepare BCPs from diverse monomers has limited the advancement of BCP based BHJ OPVs. LIMNO has advanced the field in a new report.

© 2018 Y.Liu/EPFL

Yongpeng Liu wins poster prize at nanoGE!

— At the Fall 2018 nanoGE meeting October 22-26, in Torremolinos, Málaga, Spain

© 2018 EPFL

Organic Semiconductors for Solar Fuels Reviewed by LIMNO

— Splitting water with sunlight and organic semiconductor devices is emerging as a promising approach for the inexpensive and scalable direct solar-to-fuel production.

© 2018 EPFL

Kevin Sivula nominated as Associate Professor

— The Board of the Swiss Federal Institutes of Technology has announced the appointment of four professors at EPFL. (See link for full text)

© 2018 EPFL / K.Sivula

A new application for diamonds: protecting silicon for Solar fuels

— In a collaboration with the Czech Academy of Sciences, LIMNO demonstrates a new method to stabilize semiconducting silicon for the solar-driven water oxidation reaction. 

© K. Sivula / EPFL 2018

New insight leads to record performance with photoanode material

— LIMNO reports that crystal structure disorder is a critical material parameter in the performance of ZnFe2O4 for solar fuel production.

© Yongpeng LIU / 2018 EPFL

LIMNO PhD Student Yongpeng LIU wins presentation award

— His presentation entitled "New Insights into the Role of the Semiconductor-Liquid Junction for Solar Fuel Production" at the 1st International conference of Frontier Electronic Science and Technology & Energy Materials and Nanotechnology at the University of Electronic Science andTechnology of China, May 12-16, 2018 in Chengdu, China was selected for the best presentation award.

© K. Sivula 2018 EPFL

"Green" organic photovoltaics enabled by molecular engineering

— LIMNO scientists demonstrate that molecular photovoltaics can be fabricated without toxic chlorinated solvents via melt-processing with a custom-made compatibilizer molecule.

© L.Yao / EPFL 2018

A new approach to make organic semiconducting thin films

— Dr. Liang Yao has invented a novel method to prepare semiconducting covalent polymer networks (CPNs) which greatly advances the application of these materials in optoelectronic devices. 

© N. Guijarro / 2018 EPFL

LIMNO research on spinel ferrites is chosen as cover article

— Dr. Guijarro’s detailed investigation of spinel ferrites MFe2O4 (M = Cu, Mg, Zn) as photoanodes for solar water oxidation, leads to new insights into these promising materials. The paper has been highlighted on the cover of the first issue of Sustainable Energy & Fuels in 2018. 

© K. Sivula / EPFL 2017

Passivating defects leads to record performance of WSe2

— Addressing defects is the key to high performance in solution-processed semiconducting 2D WSe2. In a new paper we report a combined strategy and benchmark results.

© K. Sivula / 2017 EPFL

Pauline Bornoz defends her thesis

— with a thesis entitled "Demonstration and Characterization of Ladder-Type Conjugated Polymer Photoanode for Direct Light-Driven Water Oxidation"

Left-to-right: Peter Uhlig (Air Liquide), Olivier Letessier (Air Liquide), Régis Reau (Air Liquide), Kevin Sivula (EPFL), Jean-Marc Girard (Air Liquide) (© Alain Herzog/EPFL)

Kevin Sivula receives Air Liquide Prize

— After winning the Air Liquide challenge in November, Professor Kevin Sivula received the Prize during a visit by senior representatives of the Air Liquide group to EPFL.

© K. Sivula / EPFL 2017

Graduations and new additions at LIMNO!

— As we begin a new school year LIMNO welcomes two new members and celebrates the successful PhD defenses of two members.

© K. Sivula /EPFL  2017

A novel nanoflake size sorting technique for 2D "layered" materials

— Dr. Xiaoyun Yu's report on the effect of flake size on 2D nanoflake WSe2 photocathodes introduces a new separation technique and employs a photogenerated carrier transport model to gain new insights into the performance of this material toward solar energy conversion.

© K.SIvula / 2017 EPFL

Morphology stabilization strategies for small-molecule BHJ OPVs

— Aiman Rahmanudin is lead author of a study that demonstrates and compares strategies to stabilize the donor:acceptor bulk heterojunction (BHJ) in organic photovoltaics.

© 2017 EPFL

New faces in LIMNO

— LIMNO engages new personnel to advance novel research directions

© K. Sivula / 2017 EPFL

Prévot et al. reveals new insights into the operation of delafossite

— In a paper published in Chem. Mater. that represents a collaboration between LIMNO and the Helmholtz-Zentrum Berlin, the charge carrier transport and surface states in CuFeO2 Photocathodes are examined, and the outlook for this material is promising. 

© 2017 K.Sivula / EPFL

The Flexible Linker Strikes Again – in a new paper from LIMNO

— Xavier Jeanbourquin et al. compare two linking strategies for solution processed small molecule semiconductors, and discover greatly different optoelectronic properties. The work is published today in J. Mater. Chem. A.

© K.SIVULA / 2017 EPFL

Dr. Florent Boudoire joins LIMNO to develop PEC devices

— Following his PhD thesis at EMPA/Uni Basel Dr. Boudoire joins LIMNO to advance photocathode development under a project with industrial collaborators (Air Liquid). Welcome Florent!

© 2017 EPFL

Xiaoyun Yu successfully defends PhD thesis!

— With a thesis entitled "Solution-processed two-dimensional transition metal dichalcogenides for solar energy conversion" Dr. Yu officially received the degree of Docteur ès Sciences on March 16th. Congratulations Dr. YU!

© K. Sivula / 2017 EPFL

LIMNO research highlighted on Reuters Video News!

— Meteorite fragments could be used as a high performing catalyst to help store renewable energy cheaply and efficiently, according to Swiss scientists. Amy Pollock reports.

© K. Sivula 2017 EPFL

Yongpeng LIU joins the group

— After a Master's degree in Nanoscience and Nanotechnology from the University of Glasgow, Yongpeng is continuing his studies in LIMNO on photoelectrochemical energy conversion devices. Welcome Yongpeng!

© K. Sivula / 2017 EPFL

LIMNO develops a new hybrid system for solar energy conversion

— Xiaoyun YU is the lead researcher on a paper published in ACS Energy Letters describing all-solution processed heterojunctions of exfoliated transition metal dichalcogenides and a perylene-diimide (PDI) derivative.

Publisher logos

Celebrate 2017 with new publications from LIMNO!

— Papers in IOP and RSC journals are released online this week. Click the link for more information.

Kevin Sivula ©EPFL

Kevin Sivula wins Werner Prize 2017

— Kevin Sivula has won the Swiss Chemical Society’s Werner Prize for 2017.

Kevin Sivula ©EPFL

Kevin Sivula wins Air Liquide challenge

— Kevin Sivula is the laureate of one of Air Liquide’s “Essential Molecules Challenge".

Gibeon Meteorite, By Hannes Grobe (Own work) [CC BY 3.0], via Wikimedia Commons

A meteorite yields a high-performance electrocatalyst

— (UPDATE: Paper highlighted by Nature!) Dr. Le Formal in our group discovered the electrocatalytic function of an iron-based Gibeon meteorite for the oxygen evolution reaction (OER) can rival the state-of-the-art performing OER catalysts. The surprizing results is published in the high impact journal Energy & Environmental Science. 

© 2016 EPFL/Sivula

LIMNO invents a novel ambipolar photoelectrode for oxygen regulation

— Wiktor Bourée in our group discovers a simple method to create a tunable bipolar n-type/p-type photoelectrode using a simple solution-processing technique and demonstrates applications in chemical regulation and switchable logic devices.

© DPP polymer structure © K. SIVULA / 2016 EPFL

New insight into effect of Molecular Weight in DPP-polymers revealed

— Gasperini, Jeanbourquin, and Sivula publish new results in the Journal of Polymer Science on Diketopyrrolopyrrole-Based Polymers in Transistor and Photovoltaic Applications

© K. Sivula / EPFL 2016

Large-Area Solar Energy Conversion with Semiconducting 2D TMDs

— Yu and Sivula publish perspective in new journal: ACS Energy Letters

© 2016 EPFL

Dr. Nestor Guijarro receives prestigious Ambizione Energy Grant

— The Swiss National science foundation approves the 3-year project entitled “Novel interfacial characterization and surface engineering in semiconductor electrodes for optimized solar fuel production” Congratulations Nestor!

© 2016 EPFL

Xiaoyun receives award from the China Scholarship Council

— Xiaoyun from our group, standing out from the competition, has been granted “the 2015 National Award for Outstanding self-financed Chinese Students Study Abroad “ by China Scholarship Council. Congratulations Xiaoyun!

© 2016 EPFL

Dr. Andrea Gasperini successfully defended his PhD thesis

— After successful private and public thesis defenses Andrea Gasperini earns the title of Docteur ès Science from EPFL. Congratulations Dr. Gasperini!

© 2016 EPFL

All-Solution-Processed High-Efficiency Chalcopyrite Photocathodes

— Dr. Guijarro has developed a facile and scalable method to prepare (Cu(In,Ga)S2) photocathodes and demonstrated their state-of-the-art performance for Solar Hydrogen production. The results have been published in Advanced Energy Materials.

© 2016 EPFL

New journal "Nature Review Materials" publishes LIMNO review

— Kevin Sivula publishes an article entitled "Semiconducting materials for photoelectrochemical energy conversion" in the new flagship review journal for the materials science and engineering community "Nature Review Materials"

© 2015 EPFL

Artificial photosynthesis using an organic semiconductor

— Pauline Bornoz in our group has discovered that a conjugated polymer known for high stability (coded as BBL) can have robust photoactivty for solar water oxidation.

© 2015 EPFL

Improving charge collection with delafossite photocathodes

— Mathieu Prévot leads efforts in LIMNO to advance inexpensive solar hydrogen production using CuFeO2 photocathodes. A new publiction  describes benchmark photocurrents using a host-guest approach.

© 2015 EPFL

Low-temperature mesoporous chalcogenide photoelectrodes

— Templating nanocrystals into mesoporous electrodes using an organic porogen typically requires thermal oxidation at >400 °C to completely remove the organic material and afford good electronic properties. Dr. Guijarro of LIMNO demonstrates in a new paper that low temperature electrodes can be prepared using a novel, autodecomposition porogen.

© 2015 EPFL

Dr. Liang Yao joins the group

— After PhD studies at Jilin University (China) in Professor Yuguang Ma's group. Dr. Liang Yao joins LIMNO. He will work towards advancing new organic semiconducting materials.

© 2015 EPFL

LIMNO Enhances the Thermal Stability of Molecular Solar-cells

— Using flexible aliphatic chains to link conjugated molecular semiconductors Andrea Gasperini developed a polymeric material that possesses defined conjugated segments but extended covalent connectivity that enhances crystallinity and thermal stability in field-effect transistors and bulk heterojunction solar-cell devices when used as an additive. The results are published in Advanced Materials.

© 2015 EPFL

A new method to make thin-films for cheap solar energy conversion

— Semiconducting materials with high crystallinity and purity constitute the top-performing solar energy conversion devices, but are still too expensive. Our group has now used 2-D layered semiconductors to develop a method to fabricate high quality thin films for solar application that is both simple and inexpensive.

© 2015 EPFL

Enhancing Photocathode Performance

— Mathieu Prévot used a facile sol-gel method to prepare tunable CuFeO2 electrodes and improve the performance. His work is published in ChemSUSChem.

© 2015 EPFL

New perspective on surface modifications

— Dr. Guijarro and Mathieu Prévot have published a perspective on surface modification of semiconductor photoelectrodes in PCCP.

After obtaining her PhD from The University of Minnesota (Prof. Eray Aydil), Dr. Melissa Johnson crossed the pond to join LIMNO. Welcome to the group ! PeopleDr. Guijarro’s use of novel overlayers of n-type CdSe or ZnSe on p-type CZTS along with a methylviologen as a surface treatment gave new insights into interfacial charge extraction (…)