Sketch a graph to show the variation of current with potential difference for a semiconductor diode in forward bias. - Leaving Cert Physics - Question h - 2006

To illustrate the relationship between current (I) and potential difference (V) for a semiconductor diode in forward bias, we need to create a graph that reflects the nonlinear characteristics of a diode.

1. Axes: Label the x-axis as 'V' (Potential Difference) and the y-axis as 'I' (Current).

2. Curve Shape: The graph should show a curve starting from the origin. Initially, as the potential difference increases from zero, the current remains low.

   • When V reaches a certain threshold (typically around 0.6 to 0.7 volts for silicon diodes), there is a sharp increase in current.
   • This is the forward bias region.

3. Nonlinear Behavior: After reaching the threshold voltage, the current increases exponentially with a further increase in potential difference, demonstrating the nonlinear behavior typical for semiconductors.

4. Correct Annotation: Ensure that the curve is smooth and continues to rise steeply beyond the threshold, indicating a significant increase in current with small increases in voltage.

By following these steps, the resulting graph would effectively demonstrate the variation of current with potential in forward bias for a semiconductor diode.