Light source of Solar cells ?

[PCBWING]

Looks very bright fluorescent light, but it can not make solar calculators work; the incandescent lamp looks very dark, it can do, what principles is it?

And how about the LED light source? I have not tried it.

Please help me to understand. Many thanks in advance!

 

[RCinFLA]

Silicon solar cells are responsive to red side of visible spectrum and into infrared region.

Fluorescent lights are heavy toward blue/ultraviolet end of spectrum.

 

[PCBWING]

Are there any ways to change the spectral characteristics of the solar cells?

 

[Sceadwian]

No, it's inherent to the materials. You could in theory use a phosphor which takes the UV/blue side and fluoresces red but practical implementation wouldn't get you much.

A white LED outputs spectral light very similar to florescent lighting (they both use phosphors to create light from blue/UV emitting sources) A red LED will probably product output from a solar cell nicely, perhaps even IR remote type LEDs. But what would be the purpose of this? The amount of retrievable light from artificial light sources is incredibly low, even solar powered calculators can sometimes have trouble and they use so little current it's ridiculous.

 

[Thunderchild]

you also need to understand that 1KW/sqm of sun light hits the earths surface but you will never have a 1KW/sqm light, oh you might think that your light is bright but it is not, our eyes are phenomenal light detectors with a far superior range than any man made sensor, our eyes adjust automatically so what you think is bright is not really bright at all and infact nothing compared to the sun, think 1KW/sqm and then think how many watts/sqm your average 100W bulb is putting in an average room bearing in mind that your looking at a source of 2-3 watts in reality as the rest goes in heat.

 

[audioguru]

My solar garden lights get very hot sitting in the sunshine all day.
Maybe the "solar panel" is actually a heat to electricity generator.

 

[Thunderchild]

well I was told that a hot solar panel is less efficient, the panel is black and so absorbs the rays very well and gets warm the same as a sheet of some black material will get warm. in any case your average room will not have 1KW/sqm of light and heat combined

 

[PCBWING]

I think I understand. I've heard people say: Even the production of food crops, there is a limit, this limit is also related with the energy of sunlight.

 

[Thunderchild]

well with crops it is down to how much space they need, and each plant is different, you can "fuel" the growth of plants with chemicals but you end up with tasteless crap

 

[PCBWING]

Solar cell problem I have learned. Thanks!
On production of food crops, I think you will have a new discovery. There is a limit: Not only because of space, but also because of the energy.

 

[Thunderchild]

well yes that does contribute as well which is why drugs are often grown under artificial light.