My understanding is that the ISS's solar panels are silicon and double sided to maximize bang-for-the-pound (average power per kilogram transported to orbit). See Are the ISS US Segment solar arrays double-sided? and the image there, and Why does the ISS not use the most efficient solar panels available? and associated images and answers.
But I don't understand the appearance of this panel in the photo below. I'm assuming the dark stuff is silicon, but there are a lot of silver/gray dots and for every four of those there is a larger interstitial red dot. And the whole think looks flexible as if it were a film rather than a crystal.
What is the structure of these devices? Are they made from amorphous flexible films of silicon, or lots of small little thin crystals of silicon on a flexible matrix of some kind? How does sunlight reach both sides - does it pass through a backing on one side?
below: Cropped and original image "Scott Kelly fixing a cooling pump during a spacewalk." from Gizomodo's Astronaut Scott Kelly on Liquid Salt, a Stinky Station, and Sleeping in Freefall. Image credit: NASA/Kjell Lindgren
below: original image shown in reduced size. (right) click for full size.