Ultrathin two-dimensional WSe2 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 WSe2 nanodots (NDs). The WSe2 NDs have hexagonal lattice structure with P63/mmc and have indirect band gap of 1.63 eV. The exfoliation and number of layers in WSe2 NDs is confirmed by Raman, absorption, and photoluminescence spectroscopy. Subsequently, the photodetector based on WSe2 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 × 1010 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.

We report a low-cost and green synthesis approach to produce high-performance optoelectronics based on WS2-decorated pencil trace on ordinary cellulose paper. It is noteworthy that the photodetector was prepared via simply nontoxic solution-processed WS2 nanosheets, pencil-drawn graphene conducting films, and biodegradable papers. Portable and flexible electronics based on WS2/graphene show excellent photoresponse in a broad spectral region from visible to near IR because of plasmonic improvement and efficient photoabsorption. Liquid-phase-exfoliated atomically thin WS2 nanosheets were decorated on a conducting film of pencil trace using the large area electrophoretic deposition technique. The photodetector based on the WS2/graphene heterostructure shows excellent temporal photoresponse with a responsivity of 0.439 A/W, a detectivity of 1.41 × 1010 Jones, and an external quantum efficiency of 81.39%. The high-performance photodetector shows piezoresistive modulation in electric transport. The device response was investigated up to 500 bending cycles. Finally, the present finding advocates the great development over previously reported nonbiodegradable and small-area optoelectronic devices.

Recent research and development is focused in an intensive manner to increase the efficiency of solar energy conversion into electrical energy via photovoltaics and photo-electrochemical reactions.

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