Cute SMD solar cells

[daqq]

I noticed cute SMD solar cells:
https://www.digikey.com/catalog/en/partgroup/ixolar/13159?mpart=KXOB22-01X8F&vendor=238

[MagicSmoker]

That conversion efficiency of 22% is impressive; usually small solar cells struggle to break 15%. Interesting find.

[DaJMasta]

They've actually been selling cells in that form factor for at least a few years, I know I've had a few tentative project ideas that have involved a couple of them and a supercap, but I've always had other things that needed doing and even with great efficiency, you'd need a clear idea of what you want the devices to do to keep within the power budget.... and I don't.


it's too bad they're a few bucks each though, if they were half the price I'd probably already have thrown a dozen into an order at some point.

[Red Squirrel]

I found some like that on digikey too when searching to see what they have as far as solar cells go.  Could be useful for very low power draw applications like calculators or even wireless sensors.   Rather expensive per watt compared to larger cells, but I guess that's to be expected.  You would not buy these if you're trying to cover your whole roof.
 

[Ushiwaka]

That cell sure is small!

[floobydust]

IXYS offers to about 1W with them. They are monocrystalline, not amorphous or polycrystalline. Look very interesting.
Exerpt from the datasheet:

Solar Cell Types
Keep in mind these cost and performance tradeoffs when comparing various solar cell materials:
Polycrystalline cells are commonly found in outdoor applications and have a spectral sensitivity range of 500nm to 1100nm. They’re in the medium price range and typically offer a 13% power conversion efficiency.
Monocrystalline cells, such as the IXYS SolarMD, have a spectral sensitivity range from 300nm (near - ultraviolet) to 1100 nm (near-infrared), which includes visible light (400 to 700 nm). Due to this wide spectral range, they can be used in both indoor and outdoor applications. Monocrystalline or single-crystalline material is the most expensive but it does not contain impurities, and as such the power conversion efficiency does not degrade over operating time. The power conversion efficiency of commercially available monocrystalline cells ranges from 15 to 22%. The surface of these cells is a homogenous dark blue or dark grey.

Finally, amorphous cells, which work in the spectral range of 300nm to 600nm, are used predominantly indoors in products such as solar powered calculators since they are not sensitive to the upper light spectrum and cannot take advantage of natural sunlight. They offer about 5% power conversion efficiency and are mostly used with ultra low power devices like clocks and electronic calculators. Amorphous cells, like polycrystalline cells, suffer from efficiency degradation.


Solar Bit Description
SolarBITs are monocrystalline, high-efficiency solar cells in a surface mount package. They’re robust and can be used in harsh environments. Solar  BITs have a very high (22 %) power  conversion efficiency, which means that 22% of the light energy is converted into electrical energy. They’re extremely useful in applications requiring solar power generation in a limited space. 

Monocrystalline cells can be used in indoor and outdoor applications because they have a wide spectral sensitivity, 300 to 1100 nm. However, the output power of a solar cell is proportional (over a wide range) to the incoming light energy, and irradiance is generally much higher outdoors. The values in the data sheet are measured at “standard condition” of 1 sun, which is equal to 1000W per square meter sunlight irradiance at a defined light spectrum (air mass of 1.5) and 25°C cell temperature.