Subcategory: STEM Research
- Alabama A&M University
Co-Author(s): B. Rami Reddy, Matthew Edwards, Ashok Batra, Satilmis Budak, Kristopher Liggins, Samuel Uba, Bir Bohara, Marcus Pugh, Vernessa Edwards, Michael Curley and Padmaja Guggilla
Effect of silver particles on the white light emission characteristics of sodium borate glasses embedded with rare-earth ions is being investigated. Glasses were made by the melt quenching technique. Silver nanoparticles were induced by heat treatment of the glass above the glass transition temperature. Diode laser excitation was used to stimulate emission from the samples. Our analysis indicates that silver particles are playing a role in enhancing the emission spectrum of the rare-earth dopants. Microscopic images of the samples were also taken to determine the distribution of silver within the glass samples before heat treatment. Preliminary results showed a 40% increment in sample fluorescence after the initial heat treatment. Sample color coordinates were close to those of white light. Thermoelectric thin films devices were prepared from Ni/Bi2Te3/Ni and Ni/Sb2Te3/Ni thin films using DC/RF Magnetron Sputtering Deposition System. They were annealed at different temperatures to see the thermal treatment effects on the efficiency of the fabricated thermoelectric devices. After thermal treatment of Ni/Bi2Te3/Ni and Ni/Sb2Te3/Ni thin film devices, their thermoelectric and optical properties were characterized using Seebeck Coefficient Measurement, van der Pauw 4-Probe Resistivity Measurement System, Laser Thermal Conductivity and Scanning Electron Microscopy Systems. Nanocomposite films of PMN-PT and PZT paints have been fabricated by the conventional paint-brushing technique on copper substrate. The pyroelectric, piezoelectric, and dielectric properties of these films were measured to explore their suitability in thermal energy conversion devices and uncooled infrared detectors. The properties investigated include: dielectric constants (ε’ and ε’’); pyroelectric coefficient (p); piezoelectric coefficient (d33) and energy conversion performance. Preliminary results indicated that paint composite films are functional and figure-of-merits increase with an increase in amount of PMN-PT nanoparticles in paint. The Khon-Sham equation of Density Functional theory, based on two fundamental theorems of quantum mechanics of many-body systems, has been used to obtain electron density calculations of confined electron systems, which have implications for the properties of matter, including energy harvesting via piezoelectric/pyroelectric effects. We illustrate preliminary results for simple confinements.
Funder Acknowledgement(s): NSF HBCU-RISE grant HRD 1546965
Faculty Advisor: None Listed,