Date of Graduation
Master of Science in Microelectronics-Photonics (MS)
Salvador B. Lopez
Morgan E. Ware
Second Committee Member
Third Committee Member
1 Dimensional, DFT, Exciton, GW-BSE, Nano wires, Quasi-Particle
The high exciton binding energy in one dimensional (1D) nano-structures makes them prominent for optoelectronic device applications, making it relevant to theoretically investigate their electronic and optical properties. Many-body effects that are not captured by the conventional density functional theory (DFT) have a huge impact in such selenium and tellurium single helical atomic chains. This work goes one step beyond DFT to include the electron self-energy effects within the GW approximation to obtain a corrected quasi-particle electronic structure. Further, the Bethe-Salpeter equation was solved to obtain the absorption spectrum and to capture excitonic effects. Results were obtained using the Hyberstein-Louie (HL), and the Golby Needs (GN) generalized plasmon pole (GPP) models. The first bound excitonic state is well localized within 50 A along the c-axis of the crystal, with a high exciton binding energy of 2.5 eV (GN) and 2.78 eV (HL) for Se and 2.09 eV for (GN) and 2.28 eV (HL) for Te nano-wire.
Andharia, Eesha Sanjay, "Quasi-Particle Band Structure and Excitonic Effects in One-Dimensional Atomic Chains" (2018). Theses and Dissertations. 3045.