SYNTHESIS, CHARACTERIZATION AND APPLICATIONS OF PHOTO ACTIVE NANOMATERIALS

There are various areas of nanoscience where novel approaches to nano or micro fabrications techniques are in constant demand, where the goal is compatibility with the system, convenience and cost rather than complexity. Electron beam lithography along with photolithography techniques are common nano or micro fabrication techniques used in semiconductor industry. Even though these techniques are common for large scale production, there exist potential applications where cost and compatibility obviate these approaches. This thesis explores a novel technique capable of fabricating micron sized fluorescent active Laser Induced Structures (LIS), optimization of the necessary instrumental parameters, and photo-physical characterization of the LIS and SrAl₂O₄: Eu, Dy phosphor material.

Here silver nanoparticles were synthesized through wet process, concentrated and drop cast onto different substrates. The resulting films were air dried and subjected to 532nm laser irradiation to produce LIS. Photo-physical characterization of LIS identified physical and chemical changes including fluorescence. A combination of Ag-polymer coating formulation was also explored for LIS formation and critical instrumental parameters were investigated. Finally a mechanism for LIS is proposed, similar to Liquid Melt Ejection (LME), validation experiments were performed. Additionally, SrAl₂O₄: Eu, Dy phosphor material was photo-physically characterized to understand its emission mechanism and was investigated against the backdrop of its effect on photovoltaic (PV) cell efficiency.