We present flexible photodetectors (PDs) for visible wavelengths fabricated by stacking centimetre-scale chemical vapour deposited (CVD) single layer graphene (SLG) and single layer CVD MoS2, both wet transferred onto a flexible polyethylene terephthalate substrate. The operation mechanism relies on injection of photoexcited electrons from MoS2 to the SLG channel. The external responsivity is 45.5A/W and the internal 570A/W at 642nm. This is at least two orders of magnitude higher than bulk-semiconductor flexible membranes and other flexible PDs based on graphene and layered materials. The photoconductive gain is up to 4x10^5. The photocurrent is in the 0.1-100 uA range. The devices are semi-transparent, with just 8% absorption at 642nm and work stably upon bending to a curvature of 6cm. These capabilities and the low voltage operation (<1V) make them attractive for wearable applications.
@article{arxiv.1512.08312,
title = {High Responsivity, Large-Area Graphene/MoS2 Flexible Photodetectors},
author = {D. De Fazio and I. Goykhman and M. Bruna and A. Eiden and S. Milana and D. Yoon and U. Sassi and M. Barbone and D. Dumcenco and K. Marinov and A. Kis and A. C. Ferrari},
journal= {arXiv preprint arXiv:1512.08312},
year = {2017}
}