Strong light-matter interactions in heterostructures of atomically thin films

• Autor(a) principal: Britnell, Líam
• Data de Publicação: 2013
• Outros Autores: Ribeiro, R. M., Eckmann, A., Jalil, R., Belle, B. D., Mishchenko, A., Kim, Y.-J., Gorbachev, R. V., Georgiou, T., Morozov, S. V., Grigorenko, A. N., Geim, A. K., Casiraghi, C., Castro Neto, A. H., Novoselov, K. S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/24485
• topic: Science & Technology

The isolation of various two-dimensional (2D) materials, and the possibility to combine them in vertical stacks, has created a new paradigm in materials science: heterostructures based on 2D crystals. Such a concept has already proven fruitful for a number of electronic applications in the area of ultrathin and flexible devices. Here we expand the range of such structures to photoactive ones by utilizing semiconducting transition metal dichalcogenides (TMDC)/graphene stacks. Van Hove singularities in the electronic density of states of TMDC guarantees enhanced light-matter interactions, leading to enhanced photon absorption and electron-hole creation (which are collected in transparent graphene electrodes). This allows development of extremely efficient flexible photovoltaic devices with photo-responsivity above 0.1 A/W (corresponding to an external quantum efficiency of above 30%).