LEDs as detectors for UV and IR. What amplifier to use?

neazoi said:

Hello, I have found from experiment that most LEDs, including UV and IR, can be used in reverse to detect the range of frequencies they are designed to emit.

I would like to make a simple detector using a transistor amplifier to drive a meter. Can I use one of these FET static detectors amplifiers and connect the LED cathode to the Gate instead?

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Audioguru said:

I think an LED would act like a tiny solar cell like a photo-diode when it has no reverse bias. If the source of the FET is grounded then light on the LED would turn off a Jfet. But it probably would not produce enough voltage to change the jfet conduction much.

If the LED had a reverse bias voltage (maximum only 5V) then light on it would increase its leakage current like a photo-diode. It might be able to turn on a Mosfet.

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