Electronics > Projects, Designs, and Technical Stuff

Measuring the Isc of small solar panel

<< < (3/3)


--- Quote from: Peabody on June 20, 2021, 04:27:01 am ---I would have thought that glass would block some of the high-energy components of sunlight, such as UV...
--- End quote ---
It does!

A photon has to have a certain amount of energy (band gap energy) to knock out an electron.
For silicon that's about 1.12 electron volt = 1100 nm, infrared.
Ultraviolet has tons (~5X) more energy but you don't get a payoff for that, just the same single electron.
(This is all Planck's constant and energy is proportional to frequency.)
At shorter wavelengths you run into limitations of the silicon and reflection.
Besides, there's not as much UV coming down as visible and infrared light.


Multi-junction solar cells have multiple band gaps and can collect the payoff of the higher energy, shorter wavelengths.

The Amazon panels turned out to be exactly as represented.  The "2.5W" has open circuit voltage of about 5.85V, and the short circuit current is 550mA.  So they will work fine.


[0] Message Index

[*] Previous page

There was an error while thanking
Go to full version