Physics - Semiconductors Question with Solution | TestHub

The given graph is plotted with Voltage ($V$) on the vertical axis and Current ($I$) on the horizontal axis.

The characteristic curve lies in the second quadrant, where $V>0$ and $I<0$. In this region, the electrical power $P=VI$ is negative, which indicates that the device is supplying electrical energy to the circuit rather than consuming it.

Let us evaluate the given options:
1. LED: Operates in forward bias, so its characteristics lie in the first quadrant ($V>0,I>0$).
2. Zener diode: Operates in the reverse breakdown region, so its characteristics lie in the third quadrant ($V<0,I<0$).
3. Photodiode: Operates in reverse bias, so its characteristics also lie in the third quadrant ($V<0,I<0$).
4. Solar cell: Generates an electromotive force (emf) when illuminated and supplies current to an external load without any external bias. Its $V-I$ characteristics lie in the second quadrant (or $I-V$ characteristics in the fourth quadrant), with intercepts corresponding to the open-circuit voltage ($V_{oc}$) and short-circuit current ($I_{sc}$).

Therefore, the given graph exhibits the characteristics of a solar cell.

Answer: Solar cell