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Solar cells are made by joining n-type and p-type semiconductor materials - Scottish Highers Physics - Question 14 - 2017
Question 14
Solar cells are made by joining n-type and p-type semiconductor materials. A layer is formed at the junction between the materials. (a) A potential difference is pr... show full transcript
Worked Solution & Example Answer:Solar cells are made by joining n-type and p-type semiconductor materials - Scottish Highers Physics - Question 14 - 2017
Step 1
Step 2
(i) Solar cells have a maximum power output for a particular irradiance of light.
Answer
From the graph, at a voltage of 2.1 V, the current is approximately 35 mA. To find the maximum power output, we use the formula:
Substituting in the values:
Therefore, the estimated maximum power output from the solar cell is approximately 0.074 W.
Step 3
(ii) Explain, in terms of photons, why the maximum output of the solar cell increases.
Answer
As the lamp is moved closer to the solar cell, the intensity of light reaching the solar cell increases. This results in a greater number of photons striking the solar cell per second. With more photons incident on the cell, more electron-hole pairs are generated, leading to an increase in current and thereby enhancing the power output of the solar cell.