Hi all.
Just found something interesting.
I found a broken 100mW burner diode (violet 405nm) which measured nearly open.
Having confirmed that it still drew a few uA I hooked up DMM on voltage range.
Well whaddaya know, narrow band UV sensor
1.5mV outside in the winter sun around 11am from the wire side (decanned) and 0.1mV from the front.
Confirmed no response to blue, green, red or infrared but a strong response at near UV from two different LEDs, a triple junction 405 and a 3mm 390.
Anyone can think of a use other than as a sunburn alerter?
Haven't tried it yet with a red or infrared but this makes sense, enough light must be hitting the semiconductor from the top to generate electrons via the PV effect.
UPDATE:- Still works fine months later.
I tried it with a defunct IR 808 and it works too.
EDIT:- also corrected the readings.
I had it up to 80mV with a nearby triple junction UV LED...
With a simple temperature compensation circuit it would make for a very effective high altitude balloon UV monitor for measuring local ozone depletion.
-A
Just found something interesting.
I found a broken 100mW burner diode (violet 405nm) which measured nearly open.
Having confirmed that it still drew a few uA I hooked up DMM on voltage range.
Well whaddaya know, narrow band UV sensor
1.5mV outside in the winter sun around 11am from the wire side (decanned) and 0.1mV from the front.
Confirmed no response to blue, green, red or infrared but a strong response at near UV from two different LEDs, a triple junction 405 and a 3mm 390.
Anyone can think of a use other than as a sunburn alerter?
Haven't tried it yet with a red or infrared but this makes sense, enough light must be hitting the semiconductor from the top to generate electrons via the PV effect.
UPDATE:- Still works fine months later.
I tried it with a defunct IR 808 and it works too.
EDIT:- also corrected the readings.
I had it up to 80mV with a nearby triple junction UV LED...
With a simple temperature compensation circuit it would make for a very effective high altitude balloon UV monitor for measuring local ozone depletion.
-A
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