1997 — 1999 |
Bawendi, Moungi Swager, Timothy (co-PI) [⬀] Nocera, Daniel [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Acquisition of Nanosecond to Sub-Picosecond Time Resolved Laser Instrumentation @ Massachusetts Institute of Technology
This award from the Chemistry Research Instrumentation and Facilities Program (CRIF), the Major Research Instrumentation (MRI) Program and the Office of Multidisciplinary Activities (OMA) will assist the Department of Chemistry at the Massachusetts Institute of Technology acquire nanosecond to sub-picosecond time-resolved laser instrumentation. This equipment will enhance research spanning the disciplines of inorganic, organic, and material chemistry. A sub-picosecond laser can provide important information about chemical reactivity. Its use may enable breakthroughs in our understanding of the properties of reactive and nonreactive molecules.
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0.915 |
1998 — 2001 |
Jensen, Klavs (co-PI) [⬀] Bawendi, Moungi Laibinis, Paul (co-PI) [⬀] Ashoori, Raymond (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Nanotechnology: Electronics of Self-Assembled Nanostructures Based On Nanocrystallite Quantum Dots @ Massachusetts Institute of Technology
9871996 Bawendi This project combines expertise in Chemistry, Physics, Chemical Engineering, and Materials Science to synthesize, process and characterize self-assembled quantum dot based nanostructures. It integrates activities for creating nanocrystalline quantum dots, surface derivatization, self- assembly, and ultra-sensitive electronic measurements and spectroscopy, to explore the chemistry and physics of single and coupled nanocrystalline quantum dots. The investigators will develop control of spatial positioning of nanocrystallites on a nanometer scale. Proteins or oligonucleotides which self-assemble will be used as directing agents for the formation of nanostructures. Each of these biomolecules can be engineered to bind to a specific ligand on the surface of a nanocrystalline quantum dot. The biological system then serves as a template for the controlled positioning of quantum dots on a surface. Ultra- sensitive charge sensing methods will be used to probe the electronic structure of such quantum dots. These measurements will address both the energetics and the extent of delocalizaton of charges inside or localized on the surface of the quantum dots. Additionally, it is planned to spectroscopically characterize charged single quantum dots. The spectroscopic properties of nanocrystalline dots are expected to strongly depend on the number of charges present in the dot, analogous to the filling of atomic orbitals; this may lead to control over the interaction of photons with the nanostructures through adjustment of the charge density on the dots. Such a capability opens the possibility of using nanocrystalline quantum dots as building blocks for microphotonic devices. The interdisciplinary collaboration combining sensitive electronic measurements with the chemical control of the dots, their environment, and their spatial positioning may allow optimization of the chemistry of the self-assembled nanostructures and the observation of new physics of confine d electrons. %%% The project addresses basic research issues in a topical area of science and engineering having high technological relevance. The research will contribute new knowledge at a fundamental level to important aspects of electronic/photonic devices. The basic knowledge and understanding gained from the research is expected to contribute to improving the performance of advanced devices by providing a fundamental understanding and a basis for designing and producing improved materials, and materials combinations. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. Graduate students will be co-advised by the four investigators across the disciplines of Chemistry, Physics, Chemical Engineering, and Materials Science integrating research and education from an interdisciplinary perspective. This research grant is made under the Nanotechnology Initiative (NSF 98-20), and is co-funded by the MPS Office of Multidisciplinary Activities(OMA), the Division of Chemical and Transport Systems, and the Division of Materials Research. ***
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2002 — 2008 |
Nocera, Daniel [⬀] Koochesfahani, Manoochehr Bawendi, Moungi |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Crc: Micro Imaging For Sensory and Materials Applications @ Massachusetts Institute of Technology
Daniel G. Nocera and Moungi G. Bawendi of MIT and Manoochehr M. Koochesfahani of Michigan State University are jointly supported by the Division of Chemistry, the Division of Chemical Transport Systems and the Office of Multidisciplinary Activities of the Mathematical and Physical Sciences Directorate for their interdisciplinary collaboration on new molecule-based optical diagnostic techniques to measure flow on small spatial scales. They will use newly synthesized fluorescent tracers based on caged laser dye molecules and nanocrystalline quantum dots to image flows at speeds of less than 1 mm/s. New optical techniques will be developed for the quantitative measurement of multivariable flow properties (e.g., flow velocity field, temperature, concentration) and transport in small dimensions. The diagnostics will interrogate important fundamental principles of flows in microchannels including transport to within 50-150 nm of surfaces. Understanding the flow behavior in microchannels is a key step in the development of active flow and mixing control on small spatial length scales. These principles defined from these flow studies will be incorporated in microchannels that contain Distributed Feedback (DFB) lasers as optical sensor elements. The integration of flow control and mixing with DFB architectures may lead to unprecedented analytical sensitivity on exquisitely small length scales. These principles are the underpinning of many emerging microdevice technologies, especially microsensors and microreactors.
Collaborative Research in Chemistry (CRC) awards are given to interdisciplinary teams of scientists working on problems of broad chemical interest. The emphasis in these awards is on new collaborative modes of research and training.
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0.915 |
2007 — 2012 |
Jensen, Klavs (co-PI) [⬀] Nocera, Daniel [⬀] Bawendi, Moungi |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Crc: High Throughput and Massively Parallel Synthesis of Nanostructured Materials @ Massachusetts Institute of Technology
Daniel G. Nocera, Moungi G. Bawendi, Klavs F. Jensen (Massachusetts Institute of Technology) and Manoochehr Koochesfahani (Michigan State University) are jointly supported to develop a microfluidic reactor for high throughput materials synthesis. This massively parallel system will allow for rapid mixing and extremely uniform segmentation, required for hydrothermal and solvatothermal synthesis. The microfluidic reactor will be fitted with sensors to provide information on chemical and physical phenomena underlying materials growth as well as allowing feedback optimization of the desired materials properties. New optical diagnostic techniques will allow microflows to be quantitatively measured. These data will allow for the control of reaction kinetics and growth processes for the creation of nanocrystals designed for optical sensing and water-splitting catalysts for solar energy conversion. The new microfluidic reactor system will enable the rapid synthesis and analysis of new materials, allowing many new compositions and combinations to be effectively studied.
This project is funded through the Collaborative Research in Chemistry Program (CRC) and provides collaborative training and research opportunities in chemistry, chemical engineering and mechanical engineering. The investigators also engage the public by discussing the role of basic scientific research in promoting societal sustainability.
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2014 — 2018 |
Jensen, Klavs [⬀] Bawendi, Moungi Kulik, Heather (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Snm: Knowledge-Based Continuous and Scalable Manufacture of Quantum Dots @ Massachusetts Institute of Technology
Semiconductor nanoparticles are attractive for enhancing the color quality and efficiency of display and lighting applications. Synthetic techniques are currently unable to produce particles that are bright, that emit color pure, and that are stable without using materials that contain toxic heavy metals. This Scalable NanoManufacturing (SNM) research project is designed to produce application ready and heavy metal free nanoparticles suitable for applications in lighting and display technologies. Experimental methods and theoretical studies will be combined to improve our general understanding of the chemical and physical forces that control nanoparticle growth. Special chemical reactors that allow the researchers to study the molecular mechanisms of nanoparticle growth will be designed. Theoretical work using computer models of the nanoparticle surface and the molecules involved in growth will be used to complement these studies and gain a deeper understanding into the processes involved. By combining the experimental and theoretical results from these experiments, the researchers intend to develop a predictive model of nanoparticle growth that will insight into possible paths for the production of heavy metal free application ready nanoparticles. This understanding will allow the researchers to design synthetic methods to produce nanoparticles that meet the requirements for implementation in lighting and display applications and provide consumers with energy efficient displays with vibrant, rich colors. This research will impact national nanotechnology challenges through publishing, patenting, and industrial collaborations. Graduate students will be educated in synthesis and scalable manufacturing of quantum dots. Undergraduate research will be an integral part of the labs through the Undergraduate Research Opportunities Program at MIT. The impact of this fundamental research on science and technology will be disseminated to the K-12 educational audience through a series of video productions.
To be attractive for use in lighting and display technologies, fluorescent nanoparticles must be efficient and bright with narrow photoluminescence spectra. Currently, the only nanoparticles that are able to meet the specifications required for high impact applications in display technologies contain the heavy metal cadmium and are based on cadmium selenide. The most promising heavy metal free substitute for quantum dots for color downshifting applications is indium phosphide. However, it is not currently possible to make indium phosphide based materials with the narrow spectral linewidths required to meet the specifications of display applications. Preliminary mechanistic studies reveal that there are substantial challenges both in understanding the dynamics and mechanistics of nanoparticle growth at the earliest stages. This work will explore the earliest stages of nanoparticle growth by using stopped flow nuclear magnetic resonance (NMR) spectroscopy to study the evolution of the reagents just after mixing. Furthermore, continuous flow systems will be integrated with mass spectrometers in order to measure and quantify the evolution of species that form early in the reaction that are not well suited to NMR characterization. These experimental measurements will be complemented and informed by theoretical techniques that model the inorganic-organic interface at the nanoparticle surface, identify potential sources of surface poisoning and explore possible methods to mitigate this problem through techniques such as etching. A comprehensive model of the factors that control the dynamics of nanoparticle growth will be developed that includes the dynamics of never-before-characterized intermediate molecular species and their interaction with the nanoparticle surface. This model will be tested using a microfluidic reactor that allows rapid, reproducible scanning of growth conditions. As it is verified, the model will be used to predict the optimal conditions for control of nanoparticle size and size distribution. The continuous flow synthesis is both well suited for the fundamental study required to improve indium phosphide synthesis as well as inherently scalable for applications in lighting and consumer electronics.
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0.915 |
2019 — 2022 |
Bawendi, Moungi Van Voorhis, Troy (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Scalable Quantum Emitters Enabled Through Rational Bottom-Up Synthesis @ Massachusetts Institute of Technology
Light sources that emit a stream of identical particles of light are critical for the advancement of light-based quantum technologies. These technologies include secure quantum communication and light-based quantum computing. Light from such sources is referred to as quantum light. Bright sources of quantum light will enable optical technologies that are unachievable with today's classical light sources, much as the development of lasers paved the way for key innovations in science and led to a large body of essential commercial applications. The research team focuses on the development of nanoparticles that can emit quantum light. These nanoparticles can be made in solution and in quantity, paving the way for the production of large numbers of identical quantum light sources. Engaging and retaining women and underrepresented minorities (URMs) in the sciences is a systemic challenge the team addresses through a variety of complementary efforts. The project encompasses pre-college outreach programs targeting K-12 students and the broader community, fostering exposure and excitement about the science conducted. Undergraduates are encouraged to obtain research experience preparing them for graduate school through a set of initiatives, especially focusing on URM students.
The project aims to develop lead halide perovskite nanocrystals capable of serving as single photon sources to enable a broad range of quantum information technology applications. The project follows a multifaceted approach combining chemical exploration of composition, shape, size and ligand environment together with computational modeling. The interplay between computational exploration and chemical synthesis allows for the design and synthesis of colloidal quantum emitters that can serve as building blocks in nano-electronic devices in a rational and scalable fashion. Current lead halide perovskite nanocrystals suffer from two main shortcomings with respect to coherent single photon emission, namely instability of the lattice and competitive dephasing. The team synthesizes and investigates new ligands and inorganic shells to suppress the dynamic twinning within the crystal and to rigidify the lattice to diminish phononic coupling, aiming to increase photon coherence times. Optimizations in composition and geometry are explored to yield faster lifetimes and improved photon purity. Construction of colloidal nano-assemblies are used to decrease lifetimes, paving the way for the development of a family of emitters with transform limited emission. Establishing this colloidal system as a viable source of quantum light critically expands the toolbox of quantum photonics.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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0.915 |
2021 — 2024 |
Bawendi, Moungi |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Designing Bright and Fast Fluorophores With Large Stokes' Shifts Based On Superradiant Molecular J-Aggregates @ Massachusetts Institute of Technology
With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the NSF division of Chemistry, Professor Moungi G. Bawendi and his team at the Massachusetts Institute of Technology will study and harness fundamental properties of molecular interactions to develop materials that generate efficient bursts of light in short timescales that are on the order of a few hundred picoseconds. Materials that can emit light quickly and efficiently have a wide range of applications, including deep-space optical communication, high-speed smart light-emitting diodes (LEDs), and quantum information technologies. Inspired by the complexity and exquisite efficiency of natural light harvesting systems, the team will explore how the optical properties of molecules can be improved by arranging them in nano- and microscale clusters called J-aggregates. In addition to this research, the team will work to make science more inclusive by providing opportunities to under-represented minorities and women in order to help develop their scientific potential and empower disadvantaged communities. In particular, the team will take part in the MIT ACCESS program that provides classes and research opportunities to students to help bridge the gap in transitioning from undergraduate to graduate school. The team will also utilize complementary programs aimed at K-12 students to convey the excitement of conducting scientific research.
This project aims to gain understanding of fundamental properties that underlie excitonic behavior, stability, and coupling in interacting molecular J-aggregates to develop materials with short lifetimes that are on the order of hundreds of picoseconds and that feature large Stokes shifts and high quantum yields. Traditional fluorophores are used in a variety of fields and have been optimized for high quantum yield, large Stokes shift, and favorable absorption cross-section. However, their application in systems that require a short response time have been limited due to their inherently long lifetimes that are typically in the nanosecond range. Coupled molecular J-aggregates have the potential to fill the need for fast, bright chromophores. The team will investigate how structural changes and environmental effects alter the excitonic behavior of molecular aggregates, and what dynamics play a role in interactions between aggregates. First, the team will study matrix effects and structural changes in nanotubular light harvesting aggregates, as well as the impact of rigidification through encapsulation in a silica shell. Second, the team will investigate origins of non-radiative loss pathways in molecular aggregates and potential ways to mitigate them. Third, the team will look at the coupling between stabilized nanotubular aggregates to understand the key dynamics involved in energy transfer between supramolecular fluorophores. This research has the potential to lead to a fundamental understanding of the properties that limit excitonic behavior and interactions of J-aggregates.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
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