Scalable and low-cost fabrication of flexible WS2 photodetectors on polycarbonate

Abstract

We present a low-cost and easy-to-implement technique to fabricate large-area WS₂ photodetector devices onto transparent and flexible polycarbonate substrates. The method relies on the deposition of large-area (in the cm scale) thin films (~30 nm thick) of WS₂ by a recently introduced abrasion-induced method. Interdigitated electrical contacts are then deposited by thermal evaporation through a shadow mask. The photodetectors present well-balanced performances with an good trade-off between responsivity (up to 144 mA/W at a source-drain voltage of 10 V and illumination power of 1 μW) and response time (down to ~70 µs) and a detectivity value of 10⁸ Jones. We found that the devices perform very reversibly upon several illumination and straining cycles and we found a moderate device-to-device variation.