EPFL Molybdenite-based Sensor

ScienceDaily, Phys.org: In 2011, an EPFL team led by Andras Kis announced molybdenite (MoS2) and its potential in various technological applications. Now they publish a paper in Nature Nanotechnology presenting a molybdenite sensor prototype.

Ultrasensitive photodetectors based on monolayer MoS2
Oriol Lopez-Sanchez, Dominik Lembke, Metin Kayci, Aleksandra Radenovic & Andras Kis

Molybdenyte is similar to graphene in his properties as a monomolecular layer. However, it has a direct badgap of 1.8eV which is said to simplify its optoelectronic applications. The new paper demonstrates "ultrasensitive" monolayer MoS2 phototransistors with improved device mobility and ON current. The devices show a maximum external photoresponsivity of 880 A/W at a wavelength of 561 nm and a photoresponse in the 400–680 nm range. The large photoresponse is apparently achieved by photoconductive gain. Here is how the phototransistor looks, from the previous publications:

EPFL Sensor Prototype