Another test with LED's, last time I didn't tested all in the junk box... now I tested the green variety, 2 in series.
The light emitter in the video is my Christmas self present, one LASER pointer that doubles as a small lantern with 2 bright white LED's. Local electronic store doesn't store LASER led's so for 2.5 Eur I had one, just have to disassemble it for further tests in light transmission. The optics su!"# big time but it works for small scale tests.
I did test also a Ge diode with a glass envelop and it did respond to the LASER light giving 21mV, it was an OA90 type I think.
Trying to scale the led's for power harvesting isn't interesting, it's cheaper to buy a small solar panel (from my head calculation) and also other solutions, will try them one of this days.