[Laser] Sensitivity of small LEDs as photodiodes

[steve kavanagh]

I have been attempting to make comparisons of several small high-intensity 625-ish nm LEDs as photodiodes for my receiver project.  All my tests show that Cree C503B-RAS LEDs are better detectors than a couple of generic Ebay types, but the results are all over the map, from slightly better to 10 times the photocurrent, depending on test method.  All of them are nominally 15 degree viewing angle 20 mA types.

Does anyone have any experience with the response of such LEDs as photodiodes, or suggestions for good test methods ?

73,
Steve VE3SMA