There are number of different types of solar panel. Nowadays only 3 are put to use:-
|Amorphous thin film||
Amorphous cells are manufactured by placing a thin film of amorphous (non crystalline) silicon onto a wide choice of surfaces. These are the least efficient and least expensive to produce of the three types. Due to the amorphous nature of the thin layer, it is flexible, and the whole solar panel can be made flexible.
One characteristic of amorphous solar cells is that their power output reduces over time, particularly during the first few months, after which time they are basically stable.
Polycrystalline (or Multicrystalline) cells are effectively a slice cut from a block of silicon, consisting of a large number of crystals.
They have a speckled reflective appearance and again you can you see the thickness of the slice.
These cells are slightly less efficient and slightly less expensive than monocrystalline cells.
The solar cells in monocrystalline panels are slices cut from pure drawn crystalline silicon bars. The entire cell is aligned in one direction, which means that when the sun is shining brightly on them at the correct angle, they are extremely efficient. So, these panels work best in bright sunshine with the sun shining directly on them