IBM Research - Almaden Science Colloquium Series - IBM Research Almaden ARC ANGELS Student Seminar Series


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Science and Technology welcomes researchers from academia and industry to present their work in Almaden's Science Colloquium Series.

Science and Technology staff who are interested in inviting researchers for this series are encouraged to contact Gavin Jones (gojones@us.ibm.com) or Greg Wallraff (gmwall@us.ibm.com) to arrange presentations. 


Topic: Formation and Operation of Sustainable Energy Materials - Batteries and Solar Cells

Speaker: Mike Toney, Ph.D. (SLAC)

Date: 1/13/2017 Time: 10:30 AM - 11:30 AM

Location: Auditorium A

Abstract: To better understand how materials atomic structure affects their function, it is essential to observe this structure during operation – operando measurements. Similarly, to understand materials synthesis, we must be able to follow the transformation pathways during synthesis (in situ investigations). This talk will give an example of both - operando X-ray scattering of Si anodes and in situ X-ray scattering and spectroscopy of the formation of hybrid organic-inorganic halide perovskite (HOIP) films - unusual solar absorbers presently of considerable interest. First, we have used X-ray reflectivity to investigate the electrochemical lithiation of single crystalline silicon (100) electrodes, which allows us to gain nanoscale, mechanistic insight into the lithiation of Si and the formation of a solid electrolyte interphase (SEI) surface film on the Si anode. From this, we can determine the evolution of the lithiated Si (LixSi) layer and the SEI layer with sub-nanometer resolution. Second, we use in situ X-ray diffraction and spectroscopy to follow the temperature kinetics of HOIP composition and crystal formation, while the HOIP films are annealed after formation from solution. This provides insight into how HOIP formation processes. 

 


TopicBridging the Opposite Worlds: Both Hyper-reactive and Stable Materials

Speaker: Prof. Sid Das (University of San Francisco)

Date: 2/3/2017 Time: 10:30 AM - 11:30 AM

Location: Auditorium A

Abstract: The design and facile synthetic route development of extremely reactive electro/photoactive materials that withstand degradation will be the focus of the talk. Our materials are (a) made using any element from the Periodic Table, (b) tuned at the atomic scale, (c) optimized to function at very fast rates (i.e. to be very reactive), and (d) made to be highly stable. This entails design and synthesis at the interface of the most energetically demanding redox reactions and fast kinetics, with the support of several spectroscopic characterization techniques (PXRD, UV-Vis, EPR, EXAFS, FTIR, TGA and AFM). This vision and methodology will enable us to overcome the core challenges in the major technological developments of the 21st century, such as batteries, solar cells, sensors and optoelectronics. Through a journey of molecular-materials by a chemist, the speaker hopes to demonstrate that freeing man-made materials from the compromise between the seemingly opposing worlds of reactivity and stability is not far-fetched and is essential for the progress of humanity in this and coming centuries. 

 


Topic: Supramolecular Biomaterials: From Fundamentals To Advanced Healthcare Solutions

Speaker: Prof. Eric Appel (Stanford University)

Date: 2/24/2017 Time: 10:30 AM - 11:30 AM

Location: J2-109

Abstract: Hydrogels are an important class of biomaterial that have received much attention for tissue engineering and controlled drug-delivery applications on account of their similarity to soft biological tissue and highly tunable mechanical properties. Supramolecular hydrogels are dynamically cross-linked polymer networks exhibiting viscous flow under shear stress (shear-thinning) and rapid recovery of mechanical properties when the applied stress is relaxed (self-healing). These properties allow for minimally invasive implantation in vivo though direct injection or catheter delivery, contributing to rapid growth in interest in their application in drug delivery and tissue engineering. Moreover, the ability to specifically tune the kinetics and thermodynamics of supramolecular crosslinking interactions affords unique opportunities to study solute diffusion through dynamic hydrogels. In this talk, the preparation and application of shear-thinning, injectable hydrogels driven by non-covalent interactions between modified biopolymers (BPs) and biodegradable nanoparticles (NPs) will be discussed. Owing to the non-covalent interactions between NPs and BPs, the hydrogels flow under applied stress and their mechanical properties recover completely within seconds when the stress is relaxed, demonstrating the shear-thinning and injectable nature of the material. Moreover, the hierarchical construction of these biphasic hydrogels allows for multiple therapeutic compounds to be entrapped simultaneously and delivered with differential release profiles in vitro and in vivo. Delivery of the loaded therapeutics can be tuned over several months, enabling long-term treatment strategies for chronic diseases and unique opportunities to study and leverage the immune system in fighting disease. Overall, this presentation will describe the generation and characterization of supramolecular biomaterials and the new opportunities they enable in biomedicine.

 


TopicNew Strategies for Selective Deposition of Nanoscale Materials

Speaker: Prof. Stacey Bent (Stanford University)

Date: 4/14/2017 Time: 10:30 AM - 11:30 AM

Location: Auditorium A

Abstract: With the growing need for fabrication of nanostructures, selective deposition is likely to become an important process to achieve pattern features at the ~10 nm length scale. Both two-dimensional planar geometries and three-dimensional structures will benefit from selective deposition processes, with bottom-up growth strategies providing advantages in reduced process complexity and improved pattern fidelity. In this presentation, we will describe area selective deposition based on atomic layer deposition (ALD). ALD is a good choice for selective deposition because its chemical specificity provides a means to achieve selectivity on a spatially patterned substrate. Typically, in area selective ALD, self-assembled monolayers (SAMs) are used to passivate the surface, using SAMs in the regions where deposition is not desired. We will show that the process provides good selectivity for thin deposited films. However, a major challenge is that after a certain amount of material is deposited, the ALD process may begin to nucleate on the part of the surface covered with the SAM. We will describe new strategies to overcome the growth on the SAM and achieve significantly higher selectivity in area selective ALD. In one approach, to improve the blocking properties of the SAM on copper surfaces, the SAM is repaired between ALD cycles with the purpose of recovering the SAM’s properties. In a second approach, a “self-correcting” process is developed in which selective deposition is combined with selective etching, greatly improving the final selectivity. With both approaches, selective ALD of more than 60 nm of metal oxide dielectric material can be achieved. We also introduce a third strategy in which the substrate surface is modified by ion implantation of fluorocarbons, enabling topographically selective ALD. In this process, we demonstrate selective anisotropic deposition in which Pt deposition is inhibited on horizontal regions but active on vertical surfaces. Future directions in area selective ALD will also be discussed. 

 


Topic: Protecting Quantum Information in Superconducting Circuits

Speaker: Prof. Michel Devoret (Yale University)

Date: 6/1/2017 Time: 10:00 AM - 11:00 AM

Location: Auditorium A

 


Topic: Recent advances in area-selective AL

Speaker: Prof. Adrie Mackus and Prof. Erwin Kessels (Eindhoven University of Technology)

Date: 6/13/2017 Time: 10:00 AM - 11:00 AM

Location: Auditorium A

Abstract: The increasingly demanding requirements in semiconductor processing for sub-10 nm technology nodes, motivates the development of advanced patterning and thin film preparation techniques based on atomic layer deposition (ALD). For a decade, the Eindhoven University of Technology has been exploring advanced ALD processing technologies and, as such, contributed to important developments in plasma-enhanced ALD, ALD-based nanopatterning, ALD for 2D materials and area-selective ALD. In the first part of the presentation, a brief overview of these activities will be given.
In the second and main part of the presentation, there will be a focus on ALD for nanopatterning and area-selective ALD . Several approaches for achieving area-selective ALD will be presented and discussed and special attention will be given to a recently developed method based on using inhibitor molecules in ABC-type ALD cycles. In this method, an inhibitor molecule is chosen that selectively adsorbs on specific materials, and subsequently blocks the precursor adsorption, resulting in area-selective deposition on those materials on which the inhibitor does not adsorb. In addition, recent results on combining area-selective ALD with selective etching will be shown. The opportunities for using these area-selective ALD processes in self-aligned fabrication schemes will be discussed.

 


Topic: 3-Dimensional Crossbar Memory Embedding Two-Terminal Rectifying Selectors for Next-Generation Computing

Speaker: K. Jean Yoon (NASA Ames)

Date: 8/11/2017 Time: 10:00 AM - 11:00 AM

Location: Auditorium A

Abstract: Crossbar memories have gathered furious attention in recent decade as a strong contender for the replacement of NAND flash memory, storage class memory, in addition to the main functioning elements in novel computing paradigms even beyond the von-Neumann architecture. Still, the main challenges toward an even higher density three-dimensional crossbar array integration include not only the complicated vertical integration process but also the critical read/write disturbance due to the presence of sneak currents in the architecture. In this talk, feasible approaches to overcome the sneak current problem is discussed, specifically based on the adoption of two-terminal selectors with rectifying I-V characteristics. The effect of such rectifying-type selectors to reading/writing margin of a crossbar array is analyzed through SPICE simulation, and based on the results, a powerful sensing scheme is proposed. Furthermore, a double-layer stacked three-dimensional crossbar ReRAM memory employing a high-performance diode selector is demonstrated. Besides such a non-volatile memory application, disparate logic operations will be discussed based on these switching elements.

 


Topic: Integration of Functional Liquids in Microelectronic Devices

Speaker: Bhagwati Prasad (UC Berkeley)

Date: 9/29/2017 Time: 10:30 AM - 11:30 AM

Location: Auditorium A

Abstract: Field-effect gating with solid dielectrics is the basis for modern electronics. Electrolyte gating, however, offers far higher polarizations. Indeed, electrolyte gating has been a breakthrough to electrically induce numerous phase transitions in solids. These experiments are all done by dripping mm-size drops of the electrolytes onto the active sample. Compared to integrated circuit technology this approach seems “stone-age” to us. These drops are open to the environment, and allow only for limited purity and reproducibility.
Heterostructure electronic circuits have, up to now, been comprised of solid materials only. We have opened this materials space to also include liquids. We demonstrate integrated liquid capacitors and integrated liquid field effect devices which are of equal quality or even outperform standard, bulk devices. This work will accelerate discoveries based on electrolyte gating by providing a new platform, and opens a new area to exploit liquid/solid interfaces in integrated functional devices with technological promise.

 


Topic: Bypassing Exascale computing with Machine Learning and Quantum Computing for Chemical Sciences

Speaker: Bert de Jong (Lawrence Berkeley National Laboratory)

Date: 11/3/2017 Time: 10:30 AM - 11:30 AM

Location: H2-214

Abstract: With exascale computing slated to arrive in the next 5 years, the field of chemical sciences is expected to see a boost in scientific discovery. However, many scientifically and industrially relevant chemical science problems are exponentially complex, and would require computing sources well beyond the exascale. Both machine learning, and more recently quantum computing may provide viable alternatives to solve many relevant chemical science problems. In this talk I will give a brief overview of the current efforts in our group towards development efforts and utilization of machine learning and quantum computing to aid scientific discovery in chemical sciences. In addition to current work, I will discuss some of our research ideas going forward, with the goal of stimulating discussions and collaborative efforts.

 


 

 

 

 

 

 

 

 

 

 

 

 

 

 




Director

Spike Narayan

Spike Narayan

Dr. Spike Narayan
Director
Science & Technology

"Mind, like a parachute, works best when open"
- Anonymous

"Any sufficiently advanced technology is indistinguishable from magic."
- Arthur C. Clarke

"If we knew what it was we were doing, it would not be called research, would it?"
- Albert Einstein