GATE 2018 EC – Question 54
A solar cell of area 1.0 cm$^2$, operating at 1.0 sun intensity, has a short circuit current of 20 mA, and an open circuit voltage of 0.65 V. Assuming room temperature operation and thermal equivalent voltage of 26 mV, the open circuit voltage (in volts, correct to two decimal places) at 0.2 sun intensity is ________.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 0.60 to 0.62
Explanation
$V_{oc}=V_T\ln\frac{I_{sc}}{I_s}$, and $I_{sc}$ is proportional to the intensity. At 0.2 sun the open circuit voltage falls by $V_T\ln5$: $V_{oc}=0.65-0.026\ln5=0.65-0.042=0.61$ V.