We know that the PN junctions, diodes, photo diodes (LEDS and photodetectors) have similar physical structure. But +ve and -ve terminals and direction of currents depends on how the device is being operated.Consider following PN junctions with light shining on it, such that hv > Eg. Here E,is the band gap of the semiconductor material of the PN junction.

We are considering three cases of using the PN-junction, as shown in the first column of the table. Fill in the table based on your understanding of rectifier diodes, photodetectors and solar-cells.