Question

Show the shape of the characteristics of a diode.

Hint:

In the V-I characteristics of a diode, current remains low in reverse bias until breakdown, and increases exponentially in forward bias after the threshold voltage.

Answer 1

The V-I characteristics of a diode are typically divided into two regions:
1. **Forward Bias Region:** When the p-side of the diode is connected to the positive terminal of the battery, and the n-side is connected to the negative terminal. In this region, the current increases exponentially as the voltage increases. Initially, there is very little current, but once the threshold voltage (typically around 0.7 V for silicon diodes) is reached, the current rises sharply.
2. **Reverse Bias Region:** When the diode is reverse biased, the current remains very small (almost zero) until the reverse breakdown voltage is reached. After that, the current increases drastically in the reverse direction.
The graph of the diode's V-I characteristics looks like this: \[ \begin{array}{c} \text{Current (I)}
\quad |
\quad | \quad \text{(reverse bias)} \quad \quad \text{(forward bias)}
\quad |
\quad | \quad \text{Threshold}
\quad | \quad \text{voltage}
\quad | \quad \text{I (increase)}
\quad | \quad \text{exponentially}
\quad |
\quad |
\quad |
\quad | \quad \quad \text{voltage (V)} \end{array} \]