Descripción del proyecto
Unas cúpulas diminutas con propiedades ópticas novedosas dan paso a dispositivos optoelectrónicos innovadores
Las monocapas de dicalcogenuros de metal de transición son una clase de nanoláminas bidimensionales atómicamente delgadas que consisten en un metal de transición y un calcógeno. Poseen numerosas aplicaciones debido a sus propiedades optoelectrónicas singulares. Sin embargo, antes de poder aprovechar estos materiales en aplicaciones comerciales es necesario contar con rutas de fabricación rentables y reproducibles para su producción en masa. El proyecto SELENe, financiado con fondos europeos, abordará este escollo importante mediante la producción de cúpulas de una sola capa de espesor a partir de muestras multicapa mediante irradiación de hidrógeno. Estas diminutas cúpulas exóticas se caracterizarán por sus propiedades ópticas aún por explorar y su posible aplicación en estructuras optoelectrónicas de alta tecnología.
Objetivo
When transition metal dichalcogenides (TMDs) are thinned down to monolayer thickness, they exhibit a direct bang gap at the K and K’ points of the Brillouin zone, which represents a binary quantum degree of freedom, referred to as valley pseudospin. The fabrication of high quality samples is currently based on the mechanical exfoliation of monolayer flakes from bulk crystal. While this approach gives excellent results at the laboratory scale, it lacks potential for upscaling, in particular if one wants to achieve a systematic coupling with surrounding photonic structures. This drawback can be overcome by controllably creating single-layer thick domes by performing hydrogen irradiation of a multilayer TMD sample. SELENe aims at exploiting this fabrication approach to perform a paradigm-shifting experimental activity, which merges the investigation of so far unexplored fundamental electronic properties of TMDs, and the first implementation of a practical interface between TMD-based emitters and basic photonic structures. We will perform a systematic investigation of the optical properties of monolayer-thick domes formed after H irradiation and extend this by controllably applying strain via piezoelectric actuators to H-inflated domes. We will investigate the influence of the strain also on interlayer excitons formed across van der Waals heterostructures. We will achieve control of the emission intensity of the interlayer exciton in domes formed in heterobilayers, because the interlayer distance can be varied acting on the temperature, due to the condensation of H2 trapped into the dome. Finally, it is possible to selectively expose prescribed regions of a sample to H irradiation by defining openings in H-opaque masks. We will take advantage of this approach by making use of electron-beam lithography to fabricate nanometer-sized domes, which we will then exploit as site-controlled emitters and for coupling into waveguides and photonic crystal cavities.
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MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinador
00185 Roma
Italia