Paper-Based Flexible Photodetector Functionalized by WSe2 Nanodots

Ultrathin two-dimensional WSe 2 has attracted huge attention due to its potential applications in future wearable electronics. Here, we demonstrate the flexible and high-performance photodetector using high-yield sonochemical exfoliation technique. An efficient and low cost fabrication strategy using Whatman filter paper is adopted for the first time for fabrication of a photodetector based on WSe 2 nanodots (NDs). The WSe 2 NDs have hexagonal lattice structure with P 6 3 / mmc and have indirect band gap of 1.63 eV. The exfoliation and number of layers in WSe 2 NDs is confirmed by Raman, absorption, and photoluminescence spectroscopy. Subsequently, the photodetector based on WSe 2 NDs is fabricated. The device shows excellent photoresponse with response time of 0.68 s and photoresponsivity of 17.78 mAW –1 and detectivity of 5.86 × 10 10 Jones for 5 V. The device is analyzed for bias of 0 to 100 V and responsivity is enhanced up to 796.18 mA W –1 at 100 V bias. Furthermore, the paper-based detector exhibited great flexibility and air stability. The performance of the photodetector was also recorded in the spectral range 390 to 880 nm. Over all, the performance paper-based device advocates a novel pathway for flexible and intelligent electronics.