Autor segons l'article: La Hera, VM; Mena, J; Canto-Aguilar, EJ; Barzegar, HR; Carvajal, JJ; Wågberg, T; Gracia-Espino, E
Departament: Química Física i Inorgànica
Autor/s de la URV: Carvajal Martí, Joan Josep
Paraules clau: Work function Surface Oxygen-chemisorption Growth Gan
Resum: In this work, the morphology, surface composition, and electronic properties of porous GaN films containing hexagonal V-shaped pits were studied. The V-pits are orientated along the [0001] direction of GaN, and we observed a clear relation between the growth time with the surface composition, film thickness, and pit morphology, which in turn had a significant impact on the band gap, valence band maximum, and the work function. The effect on the position of the valence band maximum and work function is explained by the formation of superficial oxygen-rich phases such as Ga2O3 and nonstoichiometric GaNxOy as supported by X-ray photoelectron spectroscopy and density functional theory (DFT). We further show a change in the optical band gap with the thickness of the porous films explained by a change in the tensile strain caused by open-core screw dislocations that gives rise to the formation of V-pits. The correlation between strain and the band gap is supported by DFT calculations. Our study provides insights into the intricate relation between surface states and electronic properties of semiconducting materials and offers directions for designing GaN heterojunctions with specific optical and electronic properties.
Àrees temàtiques: Surfaces, coatings and films Química Physical and theoretical chemistry Nanoscience and nanotechnology Nanoscience & nanotechnology Medicina ii Medicina i Materials science, multidisciplinary Materiais Interdisciplinar General energy Farmacia Ensino Engenharias iv Engenharias iii Engenharias ii Engenharias i Energy (miscellaneous) Energy (all) Electronic, optical and magnetic materials Ciências biológicas iii Ciências biológicas ii Ciências biológicas i Ciências ambientais Ciências agrárias i Chemistry, physical Biotecnología Biodiversidade Astronomia / física
Accès a la llicència d'ús: https://creativecommons.org/licenses/by/3.0/es/
Adreça de correu electrònic de l'autor: joanjosep.carvajal@urv.cat
Identificador de l'autor: 0000-0002-4389-7298
Data d'alta del registre: 2024-08-03
Versió de l'article dipositat: info:eu-repo/semantics/publishedVersion
Enllaç font original: https://pubs.acs.org/doi/full/10.1021/acs.jpcc.3c05878
URL Document de llicència: https://repositori.urv.cat/ca/proteccio-de-dades/
Referència a l'article segons font original: Journal Of Physical Chemistry c. 127 (51): 24658-24665
Referència de l'ítem segons les normes APA: La Hera, VM; Mena, J; Canto-Aguilar, EJ; Barzegar, HR; Carvajal, JJ; Wågberg, T; Gracia-Espino, E (2023). Electronic Properties of Hexagonal V-Shaped Gallium Nitride Pits. Journal Of Physical Chemistry c, 127(51), 24658-24665. DOI: 10.1021/acs.jpcc.3c05878
DOI de l'article: 10.1021/acs.jpcc.3c05878
Entitat: Universitat Rovira i Virgili
Any de publicació de la revista: 2023
Tipus de publicació: Journal Publications