While watching How It's Made episode on CCDs, this just springed to my mind... I always though of CCDs as of some kind of alien technology. Only now I realized that it's just an array of silica crystals that, same that we use for generating power but all connected to CPU for processing. Is this correct?
Yes, the actual light sensor in any CCD or CMOS imaging device is an ordinary silicon photodiode. However, there's just one silicon crystal (wafer), not an "array of silica crystals". Silica is silicon dioxide, which is an insulator, not a semiconductor.
The difference is that in a solar cell, you make one big diode that covers the entire chip/wafer so that you can get lots of current, but in an imaging device, you make millions of tiny diodes, along with the circuitry to sequentially read out the charges that they produce.
That is indeed the essence of it. CCD's either generate tiny charges upon being hit with light, or otherwise alter the accumulation of charges by the effects of light hitting them. They are made so small, so numerous, and so closely packed together that they can be used to reconstruct a fine-grained light image of an object by reading those charges off them electronically and then stitching the result together in software.