Fig. 4. (a) Photodetection measurement set-up comprising of an arbitrary waveform generator as a source of pulses to provide input to the laser source, which lases at λ ∼ 660 nm and was used to irradiate the DUT placed in the probe station. The semiconductor device analyzer is used to measure the photocurrent output. (b) Variation of laser power Plaser with the input voltage Vwg. The magnitude of the Plaser is altered by changing the Vwg. Higher Vwg leads to higher Plaser generation. (c) Variation in photoresponse of the inkjet printed graphene–WS2–graphene heterostructure device for three levels of Plaser used. The Plaser is directly proportional to photocurrent generation, where the higher Plaser generates a larger number of charge carriers which leads to a higher photocurrent.
