Nope there are two types for real they look the same but don't work the same so you really have three kinds to deal with from radio shack a real phototransistor and Photovoltaics and Photoconductors.
You can even use a red led as a Photovoltaics.
Photodiodes are semiconductors that produce current flow when they absorb light. In application, there are two types of photodiodes: 1) photovoltaics and 2) photoconductors.Photovoltaics work like solar cells (in fact they are the same). When light shines on the photodiode, a voltage is created across it, causing current to flow.
Photoconductors are reverse-biased photodiodes. When light shines on the photodiode, the resistance to the reverse-bias decreases. By measuring the current through the photodiode, you can detect the intensity of light.
Comparison
Frequency Response
Photodiodes are much faster than phototransistors (nanoseconds vs. microseconds)
Gain
Phototransistors have a higher gain. Photodiodes require an amplifier to use.
Temperature Response
Photodiodes vary less with temperature
ApplicationsOptocoupler
Optocouplers are used in electronics-sensitive applications. For example, you may use this in a mobile robot application to separate the microcontroller circuitry (low voltage/power) from the motor driver circuitry (high voltage/power).
Well I guess as I think about it you could say there's two kinds or two ways to use a photodiode
But there are photodiodes made to be used just one way and as by product it could work both ways I don't have both of them anymore But one made current and one didn't.
But the red led makes about 480mA with the IR light at about a haft inch away.