Direct WS2 photodetector fabrication on a flexible substrate

Recently, research to find novel two-dimensional (2D)-layered materials has attracted attention due to their advantages in flexible device applications. Thus, we directly fabricated photodetectors based on tungsten disulfide (WS2) on a flexible substrate using radio frequency (RF) magnetron sputtering and electron beam irradiation (EBI). The photoresponsivity of the WS2 photodetectors at laser illumination wavelengths of 450, 532, and 635 nm increased by 1506, 1677, and 1710 times, respectively, after EBI treatment. Furthermore, the rise and fall times decreased by 1-2 orders of magnitude after EBI treatment. The mechanical durability of the flexible WS2-based photodetectors was confirmed using static and cyclic bending testing, showing a small loss in performance (>10%) after continued bending.