Typical electrical transport properties of the single CdS NB MESFETs. (a) The current–voltage (I-V) curve measured between the source and drain electrodes. Inset: a typical FESEM image of a single CdS NB MESFET-based photodetector. (b) The red straight line shows the fitting result with the equation where I
is the reverse saturation current, q is the electronic charge, V is the applied bias, n is the diode ideality factor, k is the Bolzmann constant, and T is the absolute temperature.