The cell was 1 square centimeter in size, consisting of a 200 - micron - thick silicon layer topped with a 1 - micron - thick perovskite layer. (scientificamerican.com)
The illustration shows the structure of the sample: n - doped silicon layer (black), a thin silicon oxide layer (gray), an intermediate layer (yellow) and finally the protective layer (brown) to which the catalysing particles are applied. (sciencedaily.com)
According to Popup City, «choice of material for the front façade is unusual: the architects chose a semi-transparent silicon layer which together with the large window in the back creates a space that is flooded with light.» (treehugger.com)