aspuru-list December 2016

aspuru-list@lists.fas.harvard.edu

13 participants
34 discussions

[Aspuru-Guzik Group List] Group meeting, Thu Dec 08, 3:30 PM, Div Room

by Ian Kivlichan

Hi all, Christoph will talk at group meeting today (with traditional German Christmas cookies, for those who don't read abstracts ;)). This is the last group meeting of the semester, and I'm going to start organizing for the new year soon - if you have a talk you'd like to practice (job, GAC, conference, etc) please let me know and we can schedule it in. The schedule is here <https://docs.google.com/spreadsheets/d/1LioqdopHr5ZAmn0GaCQwLUTYoU4ZJuvfrMY…> for reference. All the best, Ian ----------- 'Light-Harvesting and Energy Transfer in Photosynthesis' In my talk I will give an introduction to energy transfer in pigment protein complexes. First, I will discuss microscopic transfer mechanisms of the Fenna-Matthews-Olson (FMO) complex. This protein functions as an energy wire in the photosynthetic apparatus of Green-Sulfur Bacteria, and transfers energy with remarkably high quantum efficiency from the clorosome antenna to the reaction center. While in the FMO complex energy flows along pathways of strongly coupled pigments, the situation is less obvious in the PC645 bilin-protein. Apart from a strongly coupled dimeric core, there is only a weak coupling between the individual pigments. Nevertheless, experimental spectroscopy reveals that energy flows along very specific pathways. We will show that the coupling to the vibrational environment plays a non-trivial role, which demonstrates that energy transfer is tunable by engineering the spectral density. I will close with a brief outlook about future directions on my research. In particular, I will discuss our first ansatz to use machine learning tools to predict transfer properties in light-harvesting networks. ps: there will be some traditional German Christmas cookies

7 years, 4 months

[Aspuru-Guzik Group List] Fwd: Postdoctoral positions at UC Irvine in theoretical nonlinear X ray spectroscopy

by Alan Aspuru-Guzik

Alán Aspuru-Guzik | Professor of Chemistry and Chemical Biology Harvard University | 12 Oxford Street, Room M138 | Cambridge, MA 02138 (617)-384-8188 | http://aspuru.chem.harvard.edu | http://about.me/aspuru ---------- Forwarded message ---------- From: Shaul Mukamel <smukamel(a)uci.edu> Date: Wed, Dec 7, 2016 at 12:54 PM Subject: Postdoctoral positions at UC Irvine in theoretical nonlinear X ray spectroscopy To: mukamelpostdocnew(a)chem.uci.edu [image: SaneBox] *SaneAttachments*: The attachments in this email have been copied to Dropbox by the magic of SaneBox <http://sanebox.com>. Click link bellow: postdoc announce DEC 2016.pdf <https://db.tt/JdezLPFmZO> - Dropbox/SaneBox/Shaul Mukamel/Postdoctoral positions at UC Irvine in ..., 2016-12-07 03.54.49 PM/ * Click the link above or find it in Dropbox with the path of the file provided next to the link. You can also forward this email as usual. Learn more <http://help.sanebox.com/customer/portal/articles/473528-sane-attachments>. * ------------------------------ Dear colleague, I would appreciate it if you could post this announcement and bring it to the attention of suitable candidates I apologize if you have received this in duplicate. Thanks, Shaul Mukamel

7 years, 4 months

[Aspuru-Guzik Group List] Excitonics Seminar: Libai Huang, Dec. 13, RM 36-428

by Catherine M Bourgeois

Please post and forward to your groups CENTER FOR EXCITONICS Seminar Series presents: Ultrafast Nanoscopy of Energy and Charge Transport December 13, 2016 at 4:30pm/36-428 Libai Huang Purdue University, Department of Physical Chemistry [Huang, Libai] The frontier in solar energy research now lies in learning how to integrate functional entities across multiple length scales to create optimal devices. Advancing the field requires transformative experimental tools that probe energy transfer processes from the nano to the meso lengthscales. To address this challenge, we aim to understand multi-scale energy transport across both multiple length and time scales, coupling simultaneous high spatial, structural, and temporal resolution. In my talk, I will focus on our recent progress on visualization of exciton and charge transport in solar energy harvesting materials from the nano to mesoscale employing ultrafast optical nanoscopy. With approaches that combine spatial and temporal resolutions, we have recently revealed a new singlet-mediated triplet transport mechanism in certain singlet fission materials. This work demonstrates a new triplet exciton transport mechanism leading to favorable long-range triplet exciton diffusion on the picosecond and nanosecond timescales for solar cell applications. We have also performed a direct measurement of carrier transport in space and in time by mapping carrier density with simultaneous ultrafast time resolution and 50 nm spatial precision in perovskite thin films using transient absorption microscopy. These results directly visualize long-range carrier transport of 220nm in 2 ns for solution-processed polycrystalline CH3NH3PbI3 thin films. The spatially and temporally resolved measurements reported here underscore the importance of the local morphology and establish an important first step towards discerning the underlying transport properties of perovskite materials. Dr. Libai Huang received her B.S. in Chemistry at Peking University, Beijing, China in 2001. In 2006, she earned her Ph.D. in Chemistry at the University of Rochester in Rochester, New York. From 2006-2008, she was a postdoctoral fellow at Argonne National Laboratory in Lemont, Illinois. She currently is Assistant Professor in the Department of Chemistry at Purdue University. Her research focuses on spatial mapping of ultrafast carrier and exciton dynamics, visualization of ultrafast energy and charge propagation at the nanoscale, femtosecond temporal resolution and nanometer spatial resolution, and ultrafast spectroscopy and nonlinear optical microscopy: Research<https://www.chem.purdue.edu/people/directory/faculty/details/107>. The Center For Excitonics Is An Energy Frontier Research Center Funded By The U.S. Department Of Energy, Office Of Science And Office Of Basic Energy Sciences Light refreshments will be served.

7 years, 4 months

[Aspuru-Guzik Group List] Cookies

by Felixander Negron

Good afternoon everyone, We have cookies in the war room. Feel free to swing by and grab one! Felix *Felixander Negron* *Laboratory Administrator * *Aspuru-Guzik Group* *Harvard University **Department of Chemistry and Chemical Biology* *12 Oxford St. M 136* *Cambridge, MA 02138* *P:** (617) 496-9964** F: **617-496-9411*

7 years, 4 months

[Aspuru-Guzik Group List] [December 22-January 10] Letters and Siria's Vacation

by Siria Serrano

Dear Group, Good morning! Please note that I will be on vacation* December 22nd to January 10th*. No letters, email, or work of any kind, will be done by me during this time so please plan all letter requests and manage deadlines accordingly. If you have any questions or concerns, please feel free to swing by and speak to me or email me directly. Cheers to all, Siria -- *Siria Serrano* *Faculty Assistant* *Aspuru-Guzik Group* *Harvard University **Department of Chemistry and Chemical Biology* *12 Oxford St. M 136* *Cambridge, MA 02138* *P:** (617) 496-1716 <%28617%29%20496-1716>** F: **617-496-9411 <617-496-9411>*

7 years, 4 months

[Aspuru-Guzik Group List] Slack

by Alan Aspuru-Guzik

Dear group members, I just upgraded our Slack to Slack basic. We should now have history for all our previous conversation available forever. We can also have guests in channels, so feel free to invite guests like e.g. Peter McMahon to specific channels. Remember to sign up and use it. I made Siria and Felix admins so they can also add you to the Slack. Alan Alán Aspuru-Guzik | Professor of Chemistry and Chemical Biology Harvard University | 12 Oxford Street, Room M138 | Cambridge, MA 02138 (617)-384-8188 | http://aspuru.chem.harvard.edu | http://about.me/aspuru

7 years, 4 months

[Aspuru-Guzik Group List] Perovskite Symposium at NOON TODAY in RM: 36-462

by Catherine M Bourgeois

CENTER FOR EXCITONICS PRESENTS PEROVSKITE SYMPOSIUM TODAY at 12 noon in the RLE ALLEN ROOM: 36-462 Come hear experts on perovskite materials and solar cells, each giving a 30 min talk about device and materials characterization, including a talk about toxicity of Pb-perovskites. Summary and the titles are below. Click on link for more details or see attached flyer. Refreshments will be served at 1pm. Please join us at 12 noon! DATE SPEAKER TITLE December 5, 2016 Dr. Antonio Abate Adolphe Merkle Institute, in Fribourg, Switzerland Ion migration in perovskite solar cells induces reversible performance losses over day/night cycling<http://www.rle.mit.edu/excitonics/events/perovskite-symposium-ion-migration…> December 5, 2016 Miguel Anaya Institute of Materials Science, Seville Optical modelling of ABX3 perovskites for solar cells with improved performance<http://www.rle.mit.edu/excitonics/events/optical-modelling-of-abx3-perovski…> December 5, 2016 Aslihan Babayigit Nanostructure Physics Group, Institute for Materials Research-IMEC, BE From cradle to grave: “The toxicity of organometal halide perovskite solar cells”<http://www.rle.mit.edu/excitonics/events/from-cradle-to-grave-the-toxicity-…> December 5, 2016 Bert Conings Research Foundation Flanders (FWO) Fellow, Hasselt University Perovskite photovoltaics—the first real contender for silicon?<http://www.rle.mit.edu/excitonics/events/perovskite-photovoltaics-the-first…>

7 years, 4 months

[Aspuru-Guzik Group List] Perovskite Mini-Symposium at NOON TODAY_EFRC-Center for Excitonics

by Juan-Pablo Correa-Baena

Location: *36-462* Time: *12 noon - 2:15PM* with opportunity to interact with the speakers until 4PM. *Refreshments will be served* Dear colleagues, Sorry for the late announcement. Today we have visitors from Europe, experts on* perovskite materials and solar cells, *They will be giving *30 min talks about device and materials characterization, *including a interesting talk about toxicity of Pb-perovskites. Summary and the titles are below. Each talk will be 30 min, *refreshments will be served*. Please join at 12 noon! Regards, Juan-Pablo Correa-Baena, PhD. Postdoctoral Researcher Massachusetts Institute of Technology (MIT) Cambridge, MA, USA email: jpcorrea(a)mit.edu web: http://pv.mit.edu/ DATE SPEAKER TITLE TIME/LOCATION December 5, 2016 *Dr. Antonio Abate* Adolphe Merkle Institute, in Fribourg, Switzerland Ion migration in perovskite solar cells induces reversible performance losses over day/night cycling <http://www.rle.mit.edu/excitonics/events/perovskite-symposium-ion-migration…> Perovskite Symposium: 12pm-4pm/ 36-462 December 5, 2016 *Miguel Anaya * Institute of Materials Science, Seville Optical modelling of ABX3 perovskites for solar cells with improved performance <http://www.rle.mit.edu/excitonics/events/optical-modelling-of-abx3-perovski…> Perovskite Symposium: 12pm-4pm/ 36-462 December 5, 2016 *Aslihan Babayigit* Nanostructure Physics Group, Institute for Materials Research-IMEC, BE From cradle to grave: “The toxicity of organometal halide perovskite solar cells” <http://www.rle.mit.edu/excitonics/events/from-cradle-to-grave-the-toxicity-…> Perovskite Symposium: 12pm-4pm/ 36-462 December 5, 2016 *Bert Conings* Research Foundation Flanders (FWO) Fellow, Hasselt University Perovskite photovoltaics—the first real contender for silicon? <http://www.rle.mit.edu/excitonics/events/perovskite-photovoltaics-the-first…>

7 years, 4 months

[Aspuru-Guzik Group List] Free rug just let me know ASAP if you want it :)

by Alan Aspuru-Guzik

http://boston.craigslist.org/gbs/zip/5905501343.html

7 years, 5 months

[Aspuru-Guzik Group List] Special Seminar: Resistive random access memories made of 2D materials: Mon. Dec 5, 10:30 AM in 36-462 (Allen Room)

by Catherine M Bourgeois

Special Seminar: [cid:image003.jpg@01D24E05.259AA320]Resistive random access memories made of two dimensional materials Monday, December 5, 2016 10:30AM Allen Room (36-462) Prof. Mario Lanza, Institute of Functional Nano & Soft Materials, Soochow University, China The introduction of two dimensional (2D) materials in the structure of microelectronic devices is a promising strategy, not only to further improve the intrinsic performance of the devices, but also to provide them with additional capabilities, like flexibility and transparency. This methodology has given very good results in field effect transistors and super capacitors. While the research on 2D metallic and semiconducting materials is well established, the knowledge of 2D insulators and their use as dielectric in electronic devices is still very scarce. This is preoccupying because i) the interaction between 2D materials and traditional dielectrics like SiO2 and high-k is very problematic, and ii) dielectrics are key elements in digital devices, as they are necessary to provide some of the required functionalities (such as electrical fields and capacitance effects). In this seminar I will present our recent progress on 2D (layered) insulators, with special emphasis on hexagonal boron nitride (h-BN). By combining device level and nanoscale experiments with theoretical modeling we observe that h-BN is much more reliable than HfO2 as dielectric when subjected to electrical fields, which may be very useful to enlarge the lifetime of logic electronic devices. The dielectric breakdown process of h-BN may not follow the well known percolation model established for 3D dielectrics, because the speed for defect formation is anisotropic due to the different atomic interactions in-plane (covalent) and out-of-plane (van der Waals). More interestingly, h-BN shows the exciting capability of tuning its electrical resistance when subjected to specific electrical stresses, a phenomenon called resistive switching (RS). In the second part of the talk I will present an entire family of h-BN based RRAM devices with forming-free bipolar and threshold operation, low switching voltages down to 0.4V, high current on/off ratios up to 106, long retention times above 10 hours and striking low variability. We observe a very interesting parallelism between oxygen vacancies in transition metal oxides and boron vacancies in h-BN. I will also show how to tune the properties of h-BN based RRAM devices by following three different approaches: i) h-BN thickness modification, ii) h-BN grain size modification and iii) graphene interfacial electrode insertion. I will make special emphasis on the use of scalable methods for the fabrication of the devices. Mario Lanza is a Young 1000 Talent professor at Soochow University, the fastest growing university in the world during 2015-2016 according to Nature Index. Dr. Lanza got his PhD in Electronics in 2010 at the Autonomous University of Barcelona. During that time he was a visiting scholar at The University of Manchester (UK) and Deggendorf Institute of Technology (Germany), where he collaborated with Infineon Technologies and Qimonda. In 2010-2011 he was a NSFC postdoctoral fellow at Peking University (China), and in 2012-2013 got the Marie Curie IOF fellowship for working in Stanford University (USA). Dr. Lanza has published over 67 research papers, including Science and Advanced Materials, four book chapters and registered four patents (one of them funded with 1 M$). Dr. Lanza is member of the advisory board of NPG Scientific Reports and Crystal Research and Technology (Wiley-VCH), as well as symposium chair and technical committee member in several international conferences. Currently he is leading a research group formed by 17 researchers, including graduate students and postdocs. Dr. Lanza is best known for his reliability studies of nanoelectronic devices, especially those using conductive AFM, a field in which he is editing a book for Wiley-VCH. The research of his group focus on the improvement of electronic devices using 2D materials. *Light refreshment will be served*

7 years, 5 months

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aspuru-list December 2016