Research Objectives and Approaches: The objective of this research is to study and optimize the interactions of nanoparticles in memory and photonic devices. Activities carried out under this project will include the formation and thermal stability of nanocrystals of the right size, size distribution and spacing by three viable methods, understanding electron injection into the metallic and semiconductor nanoparticles, understanding electron transfer between nanoparticles and the adjacent dielectric material and integrating nanoparticles in emerging memory and photonic devices such as FinFLASH and FinLight.
Intellectual Merit The success of the proposed activity will result in high performance memory and photonics devices which are fully compatible with CMOS. This will be accompanied by gaining fundamental insight into the interface between nanocrystals and its surrounding dielectrics. The collaboration with industry leaders in memory area will further solidify the approaches used in this work and transition them into viable manufacturable processes.
Broader Impact: The successful implementation of robust nanoparticle based devices will open up new opportunities not only in electronics but also in emerging areas such as biosensors and energy efficiency. PIs at both institutions will develop educational programs such as undergraduate nanolab course, development of a a nanocamp for high school students, an engineer?s week for even younger students, and career fairs for minorities for graduate schools which will enrich the student experience and also increase diversity of the education workforce. In addition, industrial internships provided to the graduate students will foster communication of industry needs to the university, while providing a highly trained workforce for industry in the future.
A combined research effort from the University of Missouri-Columbia (UMC) and North Carolina State University (NCSU) has led to important technological advancements in the field of nanotechnology, where sub-2nm Pt nanoparticles (NP) are used for various device applications. A unique tilt target sputter system at different target angles provided different energy of arriving clusters for nanoparticle formation. Study was conducted on tuning the deposition parameters such as deposition time, power and angle to obtain a good control over Pt nanoparticle size, distribution and particle density. The ability to control the size and inter-particle distances of these nanoparticles has opened the door for more advancement and research in many fields including nanoelectronics, sensing and energy. Intellectual Merits: Pt NP with controllable size ranging from 0.5 nm to 2.5 nm with a fine tune of 0.2nm steps was achieved. These Pt NPs were utilized in various device configurations such as single electron memory device, sensors, hydrocarbon fuel cells, photo-anodes for water photolysis and high surface area catalysts. Because of their exceptionally high surface area-to-volume ratio, these NPs possess remarkable catalytic and electronic properties. By embedding these NPs between Al2O3 tunneling and blocking layers, a controllable (nanoparticle size-dependent) memory window was achieved in metal-oxide-semiconductor (MOS) structures wherein each NP served as a discrete charge storage node. The ultrafine size of the NPs and their charge confinement characteristics (enhanced Coulomb Blockade) allowed controllable charging/discharging of the NPs by injection/removal of single electrons. These Pt NPs embedded non-volatile memory structures have shown satisfactory long term non-volatility based on their retention and endurance characteristics. The room temperature synthesis and vapor phase deposition of these NPs further enabled their seamless integration with low-temperature processed, organic field effect transistors, which were further integrated as field deployable sensor platform for aromatic analyte detection. Broader Impact: Due to the unique electronic and catalytic properties of sub-2nm Pt nanoparticles, there is a great potential in their use in nanoelectronic devices, as well as, in solar cells. A large number of graduate and undergraduate students, as well as, high school students were trained in this project. One minority and two female students also participated in the project.
