AB-INITIO CALCULATION OF TWO-PHOTON ABSORPTION FOR SEMICONDUCTORS
"A theoretical derivation of two-photon absorption (2PA) from bulk, surface and 2 dimensional (2D) semiconductors, based on the length gauge analysis and the electron density operator, is formulated; the intraband r_i part and the interband r_e part of the position operator r are properly accou...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2022 |
| País: | México |
| Institución: | Centro de Investigaciones en Óptica |
| Repositorio: | Repositorio Institucional CIO |
| Idioma: | inglés |
| OAI Identifier: | oai:cio.repositorioinstitucional.mx:1002/1276 |
| Acceso en línea: | http://cio.repositorioinstitucional.mx/jspui/handle/1002/1276 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Autor/Two-photon info:eu-repo/classification/Autor/Absorption info:eu-repo/classification/Autor/Semiconductors info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/22 info:eu-repo/classification/cti/2209 |
| Sumario: | "A theoretical derivation of two-photon absorption (2PA) from bulk, surface and 2 dimensional (2D) semiconductors, based on the length gauge analysis and the electron density operator, is formulated; the intraband r_i part and the interband r_e part of the position operator r are properly accounted for. Within the independent particle approximation, the nonlinear third order susceptibility tensor χ abcd (−ω; −ω, −ω, ω) and the two-photon absorption coefficient are calculated, including the scissors correction needed to correct the well-known underestimation of the local-density-approximation band gap. Using time-reversal symmetry, it is shown that the expression for χ abcd (−ω; −ω, −ω, ω) is finite at ω = 0, avoiding nonphysical divergences presented in previous calculations when ω → 0. Ab initio band structure calculations using different pseudopotential schemes that include spin-orbit coupling are used to calculate the 2PA for several semiconductors, and the calculations are compared with available experimental results for photon energies that are below the optical band gap." |
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