Semiconductor-metal transition in semiconducting bilayer sheets of transition-metal dichalcogenides

Defect-induced photoluminescence in monolayer semiconducting transition metal dichalcogenides.

It is well established that defects strongly influence properties in two-dimensional materials. For graphene, atomic defects activate the Raman-active centrosymmetric A1g ring-breathing mode known as the D-peak. The relative intensity of this D-peak compared to the G-band peak is the most widely accepted measure of the quality of graphene films. However, no such metric exists for monolayer semi...

Photocarrier relaxation pathway in two-dimensional semiconducting transition metal dichalcogenides.

Two-dimensional crystals of semiconducting transition metal dichalcogenides absorb a large fraction of incident photons in the visible frequencies despite being atomically thin. It has been suggested that the strong absorption is due to the parallel band or 'band nesting' effect and corresponding divergence in the joint density of states. Here, we use photoluminescence excitation spectroscopy t...

Plasmons in metallic monolayer and bilayer transition metal dichalcogenides

Exciton formation in monolayer transition metal dichalcogenides.

Two-dimensional transition metal dichalcogenides provide a unique platform to study excitons in confined structures. Recently, several important aspects of excitons in these materials have been investigated in detail. However, the formation process of excitons from free carriers has yet to be understood. Here we report time-resolved measurements on the exciton formation process in monolayer sam...

Plasmon dispersion in layered transition-metal dichalcogenides

Pierluigi Cudazzo,1 Matteo Gatti,1 and Angel Rubio1,2 1Nano-Bio Spectroscopy Group and ETSF Scientific Development Centre, Departamento Fı́sica de Materiales, Universidad del Paı́s Vasco, Centro de Fı́sica de Materiales CSIC-UPV/EHU-MPC and DIPC, Avenida Tolosa 72, E-20018 San Sebastián, Spain 2Fritz-Haber-Institut der Max-Planck-Gesellschaft, Theory Department, Faradayweg 4-6, D-14195 Berlin-Dahl...