Photodiode is a light sensor (photodetector) that allows current to flow in one direction from one side to the other when it absorbs photons (light). The more light, the more current will flow. This photodiode is commonly used to detect light pulses in optical fibers and others that are sensitive to light motion, it works the opposite of a light emitting diode (see LED). So the difference is when a photodiode detects light and then creates a conductive path that allows electricity to flow. Meanwhile, the LED receives electricity and then emits light.
Are solar cells a photodiode? Solar Cell is a photodiode which is chemically processed, but it is different from the photodiode which is used as a switch or relay. When the cells in the solar cell are exposed to light, the silicon material contained in them will be attracted and move to a place where it will gradually generate an electric current. It takes a large diode cell arrangement to be able to meet the electricity needs of a house. So the conclusion is that a larger diode cell is needed to be able to generate more electricity.
This photodiode is similar to an ordinary semiconductor diode, except that the device is used to detect vacuum UV or X-rays or a device packaged using a fiber optic connection to allow light to reach more sensitive parts of the device. Whereas diodes designed for use specifically as photodiodes use PN junctions, which are useful for increasing faster responses.
How the photodiode works can be seen from the image below:
Above, it was explained that a photodiode is a semiconductor device that can convert light energy into electrical energy. Suppose an anode and cathode of a flowing diode are indicated by the meter. When the photodiode is placed in the dark, the meter will display zero, which means there is no current flow. When the photodiode is given light, it will act as an energy source causing an electric current to occur from the cathode to the anode through the current meter.
Photodiode has current characteristic which is very linear to light v / s. Commonly used as an in-camera light meter. Diodes are also often used in the manufacture of optical lenses and filters. Photodiode response will be slower with increasing surface area.