Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Laser Ablation In Liquid For The Controlled Production Of Photoluminescent Graphene Quantum Dots And Upconverting Nanoparticles, Rosemary Lynn Calabro
Laser Ablation In Liquid For The Controlled Production Of Photoluminescent Graphene Quantum Dots And Upconverting Nanoparticles, Rosemary Lynn Calabro
Theses and Dissertations--Chemistry
Photoluminescent (PL) nanomaterials play an important role in areas including displays, sensing, solar, photocatalysis, and bio applications. Traditional methods to prepare PL materials suffer many drawbacks such as harsh chemical precursors, complicated synthetic steps, and production of many byproducts. Laser ablation in liquid (LAL) has emerged as a promising alternative to prepare materials that is single-step, fast, uses fewer precursors, produces fewer side products, and has simple purification steps. During LAL, a solid target is irradiated with a pulsed laser source. The laser pulses cause plasma plumes of the target material to form which are cooled, condensed, and can react …
Designing Metal-Halide Perovskites With Enhanced Optical Properties And Stability Using Surface Ligands, Md Aslam Uddin
Designing Metal-Halide Perovskites With Enhanced Optical Properties And Stability Using Surface Ligands, Md Aslam Uddin
Theses and Dissertations--Chemistry
Metal-halide perovskites (MHPs), with formula ABX3 (A = methylammonium, formamidinium, or Cs+; B = Sn2+ or Pb2+; and X = Cl-, Br-, or I-) are versatile and attractive materials because of their tunable optical and electronic properties. These optical and electronic properties include tunable direct band gaps, high absorption coefficients, low exciton binding energies, relatively high electron and hole mobilities, narrow emission line-widths, and high photoluminescence (PL) quantum yields (ΦPL). Much of the initial excitement around organic metal-halide perovskites focused on their application in photovoltaics (PVs) …
Synthesis And Characterization Of Carbonaceous Particles From Xylose And Soybean Residuals, Shanshan Wang
Synthesis And Characterization Of Carbonaceous Particles From Xylose And Soybean Residuals, Shanshan Wang
Theses and Dissertations--Chemistry
Carbonaceous materials, especially in micro and nanoscale, are useful in optical, energy storage, electronic, and biomedical devices or technologies. Techniques have been developed for preparation and modification of the carbonaceous materials, while it is still challenging to tailor the properties of carbonaceous materials effectively and economically. Laser is a powerful tool in academic and industrial laboratories, which also plays important roles in the preparation and modification of high-performance carbonaceous nanomaterials.
In this study low-cost hydrothermal synthesis, high-temperature annealing, and Laser ablation (LAL) methods are developed to prepare functionalized carbon nanomaterials and modify their electrochemical and optical properties.
Sub-micro hollow carbon …
Photoluminescence Mechanism And Applications Of Graphene Quantum Dots, Yiyang Liu
Photoluminescence Mechanism And Applications Of Graphene Quantum Dots, Yiyang Liu
Theses and Dissertations--Chemistry
Graphene quantum dots (GQDs) are small pieces of graphene oxide whose physical dimensions are so confined (a few to a few tens nm) that they have a finite bandgap due to a quantum confinement effect. The finite bandgap of GQDs grants them pronounced absorption bands and a substantial photoluminescence. These optical properties are rarely observed in traditional carbon materials, since most of carbon materials are metallic with a near-zero bandgap and thus have broad absorption spectra with no photoluminescence. The unique optical properties of GQDs, along with GQDs’ inherited advantages from carbon material family (cheap, abundant, non-toxic), make GQDs an …