2018/03/30 by Jorge Quereda, Talieh S. Ghiasi, Jhih-Shih You +3 · 77 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Charge (physics) #Curvature #Graphene research and applications #Monolayer #Semiconductor #Spin (aerodynamics) #Symmetry (geometry) #Topological Materials and Phenomena #Voltage #Wavelength #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41467-018-05734-z
published in Nature Communications 9(1), 3346 (Nature Portfolio)
openalex created_date 2018/03/29 · arxiv created 2018/03/30 · openalex publication_date 2018/08/15 · arxiv updated 2018/10/18 · openalex updated_date 2026/08/05
Abstract In monolayer transition metal dichalcogenides helicity-dependent charge and spin photocurrents can emerge, even without applying any electrical bias, due to circular photogalvanic and photon drag effects. Exploiting such circular photocurrents (CPCs) in devices, however, requires better understanding of their behavior and physical origin. Here, we present symmetry, spectral, and electrical characteristics of CPC from excitonic interband transitions in a MoSe 2 monolayer. The dependence on bias and gate voltages reveals two different CPC contributions, dominant at different voltages and with different dependence on illumination wavelength and incidence angles. We theoretically analyze symmetry requirements for effects that can yield CPC and compare these with the observed angular dependence and symmetries that occur for our device geometry. This reveals that the observed CPC effects require a reduced device symmetry, and that effects due to Berry curvature of the electronic states do not give a significant contribution.