Figure 4: Influence of the optical power input on OEH. (a) I-V curves showing the functional dependence of currents on light intensity under fully lighted images (the entire OEH device’s surface is illuminated). Light intensities are indicated as percentages of the maximum light intensity (2 mW), with 10% increment. 0% (3 μW) corresponds to a black image. (b) and (c) Influence of light intensity on and defined in the photocurrent equation as . (d) Current against light intensity for various values of the bias voltage (log-log scale). (e) Functional dependence of γ on voltage, where γ relates photocurrents to light intensity through the power law .