Tiny Solar Cells?

I came across these tiny solar cells (they are photo diodes) but were being sold as 0.4V 1ma solar cells (I couldn't figure out what you would need a 1ma cell for)
Anyway it's a photodiode not a solar cell BPW-34 Siemens and it's only 5.1mm (0.2") across, it does put out voltage when light hits it. But it's not a solar cell is it?
**broken link removed**

PS it's a perfect fit for my Junebugs CON4 as I'm working on a Solar Logger for the JPUG newsletter.

I've seen them used in BEAM as light sensors.

Depends on what your definition of "Solar Cell" is.

I think by most peoples idea of a solar cell (a device which converts light to a voltage) THEN THIS IS CERTAINLY A "SOLAR CELL", just not a very big and powerful one.