Using Asymmetric Crystals for New Functionality: Moving Spins with Heat Using Spin-Orbit Coupling and Dopant-less Diodes Using Polarization Charge

The lack of inversion symmetry in certain crystals leads to interesting properties. Two such properties, the spin-orbit effect and polarization charge, can be exploited for new thermoelectric and optoelectronic devices. In the first part of the talk, I will introduce the heat/spin conversion phenomenon, the spin-Seebeck effect. Phonons interact with the magnetic moments in a material driving them away from equilibrium inducing a diffusive spin current, which can be converted in a neighboring material into an electric voltage.

Dielectric and Molecular "Multipole Antennas" for Energy Sciences and Technology

Solid-state lighting and solar photovoltaic devices typically employ optical materials comprising isotropic assemblies of atomic and molecular electric dipoles. Many nanomaterials, however, exhibit optical properties that are inconsistent with these simple models. In this talk we discuss novel optical phenomena arising from oriented “multipole antenna” resonances in organic materials and dielectric nanostructures.

Sustainable Buildings Research: Opportunities in Design and Operation

Gregor Henze has been involved in building sciences research for 20 years, both in the United States and Europe. This seminar will offer a discussion of case studies of sustainable energy research applied to commercial buildings and an outlook on the need for future advances. The first part of the seminar will discuss low-exergy building systems for new building design.

How to Freeze Silicon: A Many-Splendored Problem

Since the first use of silicon in electronic devices, the crystallization of silicon into useful forms for device processing has been a constant subject of both fundamental research and commercial development. To make suitable substrates for ever-smaller devices, companies have perfected the Czochralski crystal growth process for sizes up to 450 mm in diameter, with ingots up to 300 kg in weight. For use in photovoltaic applications, up to six different crystallization methods have been in production at different companies at the same time.

MIT Enterprise Forum: The Weakest Link in Renewable Energy - Clean Energy Storage

Renewable energy is unpredictable...flooding the grid one day and abandoning it the next. One answer to the grid challenge could be to store these peaks of energy.  However, today's batteries do not have nearly the capacity and they are an environmental fiasco. This Forum will bring one of the leading cleantech venture groups in California, Angeleno Group, a start-up in high powered batteries, LifeCel Technology, and an expert in the flaws in the current technologies together to discuss recent breakthroughs in energy storage. LifeCel Technology Inc.

Reversible Computing: Possibilities and Challenges

I will review physics of the so-called "thermodynamic limit" on the energy consumption at computation, and C.Bennett's idea of reversible computing, which allows that limit to be avoided. Unfortunately, even if implemented in hardware virtually free of static power consumption (such as Parametric Quantron circuits), a genuinely reversible computation would require exponentially large resources. Selective reversibility sacrifices may sharply reduce this hardware overhead, but still leave the circuit speed and defect tolerance relatively low.

Reinventing Fire: Bold Business Solutions for the New Energy Era

Amory Lovins is widely considered among the world's leading authorities on energy, especially its efficient use and sustainable supply.  As Chairman and Chief Scientist of the Rocky Mountain Institute, Lovins pioneered the concept of "soft energy paths" involving efficient energy use, diverse and renewable energy sources, with special reliance on "soft energy technologies" such as solar, wind, biofuels, geothermal, etc., matched in scale and quality to their task, and widely accessible across society.

Leveraging Renewable Energy in Data Centers

Interest has been growing in powering data centers (at least partially) with renewable or "green" sources of energy, such as solar or wind.  However, it is challenging to use these sources because, unlike the "brown" (carbon-intensive) energy drawn from the electrical grid, they are not always available.  In this talk, I will first present a case for leveraging green energy in small and medium-scale data centers.  I will then describe the solar-powered data center we have just built at Rutgers, and the lessons we have learned building it.

Compatibility, Hysteresis and the Direct Conversion of Heat to Electricity

Big first order phase transformations in solids can still be highly reversible, if the lattice parameters are “tuned” to satisfy certain relations that promote the compatibility between phases.  We present recent measurements of hysteresis in martensitic materials resulting from this kind of tuning.  We re-examine the origins of hysteresis in light of these measurements, and conclude that a certain energy barrier, not pinning or thermal activation, is primarily responsible for hysteresis in a broad array of materials that undergo phase transformations.

Solution-Processed Small-Molecule Solar Cells with 7% Efficiency

We have demonstrated efficient solution-processed small-molecule solar cells based on a novel molecular donor, DTS(PTTh2)2. A record power conversion efficiency (PCE) is achieved for small-molecule organic photovoltaics: PCE=7% under AM 1.5 G irradiation (100 mW cm–2) from bulk heterojunction (BHJ) composites of DTS(PTTh2)2:PC70BM (donor to acceptor ratio of 7:3) with short circuit current (Jsc) of 14.4 mA cm–2, open circuit voltage (Voc) of 0.78 V and fill factor (FF) of 59%.