Publicación:
Optical characterization and bandgap engineering of flat and wrinkle-textured FA0.83 Cs0.17 Pb(I1 − xBrx)3 perovskite thin films
Optical characterization and bandgap engineering of flat and wrinkle-textured FA0.83 Cs0.17 Pb(I1 − xBrx)3 perovskite thin films
No hay miniatura disponible
Fecha
2018
Autores
Tejada Esteves, Alvaro
Título de la revista
Revista ISSN
Título del volumen
Editor
Pontificia Universidad Católica del Perú
Proyectos de investigación
Unidades organizativas
Número de la revista
Abstracto
The complex refractive indices of formamidinium cesium lead mixed-halide (FA0.83Cs0.17Pb(I1 − xBrx)3) perovskite thin films of compositions ranging from x = 0 to 0.4, with both flat and wrinkle-textured surface topographies, are reported. Films are characterized using a combination of variable angle spectroscopic ellipsometry and spectral transmittance in the wavelength range of 190 nm to 850 nm. Optical constants, film thicknesses and roughness layers are obtained point-by-point by minimizing a global error function, without using optical dispersion models, and including topographical information supplied by a laser confocal microscope. To evaluate the bandgap engineering potential of the material, the optical bandgaps and Urbach energies are then accurately determined by applying a band fluctuations model for direct semiconductors, which considers both the Urbach tail and the fundamental band-to-band absorption region in a single equation. With this information, the composition yielding the optimum bandgap of 1.75 eV for a Si-perovskite tandem solar cell is determined.
Descripción
Palabras clave
Perovskita,
Óptica,
Películas delgadas