Figure 3
The transfer characteristics of (a) 33ZTO and (b) 50ZTO TFTs at VDS = 1 V measured in dark and under UV light (at 365 nm) exposure. The sample was exposed to UV light for 5 min at an intensity of 40 mW/cm2 before starting the photocurrent–voltage measurement. Insets show the sensitivity (photo-to-dark current ratio) as a function of VGS. In (c) and (d), the transient response of the drain-to-source current for ZTO photo-TFTs under a single UV light pulse of 15 min for the sample 33ZTO and 50ZTO, respectively. The inset in (c) shows photoresponse of 33ZTO under a periodic UV pulse (10 min). The inset in (d) shows extended measurement (up to 50 h) of drain-to-source photocurrent after switching off the UV light.
