This Partnerships for Innovation project from the University at Albany a.k.a. SUNY Albany (College of Nanoscale Science & Engineering (CNSE)), in collaboration with key players from the private sector and government, focuses on the area of silicon nanowire (SiNW)-related nanotechnology innovations and discoveries to optimize the properties of energy devices through the integration of SiNW materials with controlled interfaces and desired physical and chemical properties that will allow more widespread implementation of this platform technology. CNSE's unique fabrication capabilities of nanostructured materials will enable the production of interface geometries, defect structures, and atomic arrangements not otherwise possible in materials produced by traditional methods. In turn, the investigation of carrier generation, charge distribution, surface migration and charge transfer on uniquely tailored surfaces leading to better understanding and processing of these materials will be enabled. Additionally, new shared knowledge will determine how to best integrate one- and three-dimensional Si-based nanostructures and how such processes can be appropriately scaled economically.
The broader impacts of this research are on energy efficiency and clean energy technology. The project proffers advances in energy devices, including solar cells, thermoelectric devices, and batteries through improvements in SiNW architectures and nanostructured materials. This activity will build on the work of CNSE's broader incubation, commercialization, and "partnerships for innovation" efforts; which focus on connecting university-based research and development activities with private enterprise funding and expertise, which, in turn, will help increase the rate and scale of clean energy technology market penetration across the region and country. This program is expected to develop and ultimately commercialize innovations and create economic development opportunities, resulting in green jobs in the U.S., as well as ensuring independent and secure energy resources for the nation. In addition to technology development outcomes of this project, for the first time, three small business industrial partners at CNSE will get to experience and contribute to the power of leveraging the circular open innovation model. The knowledge sharing within this technology platform will result in a pipeline of new capacity with new and existing industry partners. This approach will make CNSE's new technology capabilities openly accessible to external users, allowing these outsiders to expand on and remix the core product in surprising new ways. Anticipated to arise out of input from external users will be improvement on the innovations and creation of new value that CNSE and its partners may ultimately be able to use in other industry segments.
Partners at the inception of the project include the Knowledge Enhancement Partnership (KEP) unit, consisting of University of Albany (College of Nanoscale Science & Engineering), and three small businesses: Magnolia Solar Corporation (Woburn, MA and Albany, NY), Hi-Z Technology (San Diego, CA), and B.E.S.S. Technologies (Albany, NY). In addition, there are other core partners (from the state of New York unless otherwise indicated). They include private sector organizations: CG Power, EYP/Energy, New Energy New York, and Salem Financial; these partners will provide market deployment opportunities, assist in network building and strategic partnerships, and help define specifications for renewable energy products developed by the KEP; public sector organizations: including the National Renewable Energy Laboratory (NREL) (Golden, CO), New York State Energy Research and Development Authority (NYSERDA), and New York State Empire State Development (NYSESD); these partners will support technology development, technology transfer assistance and competitive economic development assistant grants to the KEP; and other partner organizations: ECG Consulting, Heslin Rothenberg Farley Mesiti, and the Hudson Valley Center for Innovation; these partners will provide business mentoring and business planning support to the KEP.
The goal of the National Science Foundation’s Partnerships for Innovation Nanotechnology Innovations for Clean Energy – Innovative Partnerships (NSF PFI: NICE-IP) program, developed by the SUNY College of Nanoscale Science & Engineering (CNSE), is to build innovation capacity and to strengthen "innovation ecosystems" that will accelerate the movement of cutting-edge clean energy technologies incorporating nanotechnology-related innovations and discoveries from university laboratories into the market place. The ecosystems developed fostered collaborative environments, bringing together multiple value-adding players from universities, the private sector and government. The challenge in incorporating nanotechnology in clean energy applications is to effectively utilize existing knowledge of science that predicts behavior, measures characteristics at the nanoscale; and understand, design and integrate nanomaterials through a scalable production process. In addition, new knowledge can determine how to best integrate one- and three -dimensional nanostructures and how such processes can be appropriately scaled "economically". More importantly, optimizing the properties of energy devices through the integration of silicon based nanostructured materials with controlled interfaces and desired physical and chemical properties will require multidisciplinary teams and knowledge to allow for widespread realization of this platform technology. Advances in nanomaterial architectures will give rise to significant opportunities to create multifunctional materials for energy devices. Project Outcomes: YEAR I The approach and reactor design allowed precise control on the process stability, reproducibility, and purity of SiNWs for larger area samples compared to the smaller size reactor used for the research project. In addition, it was found that different thicknesses of catalyst layer leads to different SiNW morphologies, leading to a proposal that the Ni is consumed from the bottom layer and not the catalyst tip. It was found that the oxidation of nickel and the reduction of silicon plays a vital role in the cycling performance of the SiNWs. The team has shown that SiNWs grown with the VLS mechanism on stainless substrates to be used as electrode in Li-ion batteries could make this system very promising for future batteries. YEAR II NSF PFI: NICE-IP developed the VLS approach to grow SiNWs to allow better control on the process stability, reproducibility, and purity of SiNWs on the larger area samples compared to the smaller size reactor used for the research project. For the solar cell devices, Au was selected as the catalyst of choice for the SiNWs development on Si substrates. Several solar p-i-n devices with i-SiNWs were fabricated and tested. For the battery technology, the use of Ni as catalyst on stainless substrates was further developed. It was found that the oxidation of nickel and the reduction of silicon plays a vital role in the cycling performance of the SiNWs. The novelty of the solar devices fabricated is that the n-type emitter was fabricated by spin-on and diffusion process. A low cost process, which is used in by the solar cell industry as standard process for the development of high efficiency and lower cost crystalline silicon devices, has the potential to be used with SiNWs based solar devices and can be expanded in large area cells. The electrical characteristics of the devices with i-SiNWs were found to be: Isc=4.1mA, Voc=225mV, FF=24% with efficiency (n) n< 1%. Fabrication 2x SINW devices on top of p-n crystalline silicon devices could potentially lead to higher efficiency crystalline Si devices. The VLS process, with Ni catalyst on stainless steel substrate, resulted with SiNWs which consisted of an amorphous NixSiyOz shell and a NiSi polycrystalline inner core. The nanostructured material showed 81% capacity retention over 1000 cycles in a half cell design using cyclic voltammetry. YEAR III NSF PFI: NICE-IP optimized the VLS approach to grow SiNWs on larger area samples. High volume and large sample area catalytic CVD system was used to successfully grow silicon nanowires on Si substrates. Several different growth conditions for SiNWs have been tested and characterized. XRD and Raman data demonstrated that the wires are crystalline. The distribution of the average crystalline core of the SiNWs showed the majority had a diameter of about 40-50nm. NSF PFI: NICE-IP proved that the nanowires have high capacity while retaining good SEI characteristics, due to the integration of reaction displacement anode material (NiO) on the nanowire surface. The NiO passivates the surface during lithiation and insulates Si from degrading by becoming passivated by alkyl carbonate end terminations. Showed that the nanowire anode has a capacity that is 6X higher than graphite anodes and it is stable for 300 cycles. The cycle rate shows that even at a high charge rate of 10C the nanowire anode still retains a capacity of 300mAhr/g which is the tested gravimetric capacity of graphite. Demonstrated that the nanowires recover when switched from a high to a low cycle rate with no fast charging rate degradation mechanism.
