What's the difference between all these Light Sensors?

vangbe

I can't really tell the difference between..

IR Phototransister, IR Detectors, IR Receivers, Photodiode, Phototransistor, Photoresistor?

I'm sure their are more Light sensors like this, but what are they and what are all the differences?

Phil Pilgrim (PhiPi)

Phototransistor: a transistor whose base is sensitive to light and becomes forward biased when light strikes it, causing the transistor to amplify the resulting current.

IR Phototransistor: a phototransistor that's sensitive only to infrared, typically around 900 - 1100 nm wavelength.

IR Receiver: typically an IR detector that's sensitive only to infrared that is modulated, usually around 38 - 40 kHz.

IR Detector: a catch-all term for any photosensor whose peak response is in the infrared range of wavelengths.

Photoresistor: a photodector whose resistance changes in response to light impinging on it. These are typically made of cadmium sulfide (CdS).

Photodiode: a diode that, when reverse biased and its junction is exposed to light, conducts current in proportion to the light intensity. Because the current is very small, photodiodes require amplification to return an easily-measurable response.

Light-to-voltage detector: a combination of a photodiode and an op amp that converts impinging light levels to a measurable voltage.

Photovoltaic cell: an amorphous semiconductor that directly converts light to a voltage, e.g. a photocell.

-Phil