Flexible photodetectors have applications in, e.g., wearable electronics. They are usually produced from bulk semiconductors, which are relatively stiff and can only be used in the form of thin membranes or nanowires. However, in this form, their responsivity to light is decreased.
Andrea C. Ferrari, University of Cambridge, UK, and colleagues have developed flexible photodetectors made from single-layer graphene and single-layer molybdenum disulfide. The detectors have a responsivity over 2 orders of magnitude higher than for semiconductor flexible membranes. The researchers prepared the devices on a flexible polyethylene terephthalate (PET) substrate by stacking chemical-vapor-deposited (CVD) single-layer MoS2 and single-layer graphene. The molybdenum disulfide absorbs visible light, and the graphene acts as a conductor for the resulting photocurrent.
The devices could be produced with photoactive areas of several square millimeters. They are semitransparent and stable over more than 30 bending cycles. According to the team, such photodetectors could be used for wearable, biomedical, and low-power optoelectronic applications.
- High Responsivity, Large-Area Graphene/MoS2 Flexible Photodetectors,
Domenico De Fazio, Ilya Goykhman, Duhee Yoon, Matteo Bruna, Anna Eiden, Silvia Milana, Ugo Sassi, Matteo Barbone, Dumitru Dumcenco, Kolyo Marinov, Andras Kis, Andrea C. Ferrari,
ACS Nano 2016.