Identify the solar cell characteristics from the following options :

Solution

Physics sir · 3 steps

A solar cell gives out power, so its I-V curve must sit in the fourth quadrant: V positive, I negative.

1. Where current flows. Light creates electron-hole pairs, and the junction field drives them across. This photocurrent flows from n to p inside the cell, which is opposite to the forward current of a diode. The voltage across the cell is still positive (p side at higher potential), so V > 0 while I < 0.
2. Two intercepts. With the terminals shorted, V = 0 and the full short-circuit current I_(sc) flows, which marks a point on the negative I axis. With the terminals open, I = 0 and the cell shows its open-circuit voltage V_(oc), which marks a point on the positive V axis. The curve joins these two points and bends near V_(oc).

   Option	Shape of the graph	Device
   (a)	Current rises steeply after a small positive voltage, first quadrant only	Forward-biased p-n diode
   (b)	Curve in the fourth quadrant, from I_(sc) on the I axis to V_(oc) on the V axis	Solar cell
   (c)	Straight line through the origin	Ohmic resistor
   (d)	Forward rise plus a sharp reverse breakdown	Diode or Zener diode

3. So. Only graph (b) lies in the fourth quadrant with I_(sc) and V_(oc) as its intercepts, so (b) is the solar cell characteristic.

The idea to keep. A device that supplies power has V and I of opposite sign, so its curve sits in the fourth quadrant. For a solar cell, read I_(sc) on the current axis and V_(oc) on the voltage axis.

Answer from the NTA final answer key. Solution by PrepWiser.