a) Sketch an IV characteristic of a photodiode, showing how the curve shifts as a result of the illumination intensity incident on the device
being varied.

b) Indicate on the characteristic curves the photovoltaic and photoconductive regions and on one of the curves mark the approximate position of the operating point that will give maximum power output.

c) At a certain light intensity a solar cell has an open-circuit output voltage of 0.67 V. Assuming the component of reverse current produced by illumination is directly proportional to the illumination intensity, find the open-circuit output voltage when the intensity is doubled. (You may take the ideality factor, K, to be 1 for this device.)

d) An array of solar cells is to be constructed to deliver 3 A at 7.8 V under a certain light intensity. If each cell delivers 0.6 A at 0.65 V at this intensity, how many cells are required and how should they be connected?