6 Amorphous Silicon Solar Cells
147
Fig. 6.8 Cross-section of a texturized bifacial HJT solar cell with pn-junction at the back and
double-sided passivation
6.2.1 The p-i-n Structure Used for Amorphous Silicon Solar
Cells
Because of the very poor electronic quality of intrinsic
4 amorphous silicon (a-Si:H)
layers, it is not possible to use pn-diodes, to form solar cells. Indeed even the very best
intrinsic a-Si:H layers have diffusion lengths, which are well below 1 µm. Therefore,
diffusion is not a suitable transport mechanism for collecting the photo-generated
carriers within an a-Si:H solar cell. Sufficient collection only becomes possible with
the help of an electric field E, i.e. by using drift as transport mechanism. To obtain a
4 Doped (a-Si:H) layers have even poorer quality.
147
Fig. 6.8 Cross-section of a texturized bifacial HJT solar cell with pn-junction at the back and
double-sided passivation
6.2.1 The p-i-n Structure Used for Amorphous Silicon Solar
Cells
Because of the very poor electronic quality of intrinsic
4 amorphous silicon (a-Si:H)
layers, it is not possible to use pn-diodes, to form solar cells. Indeed even the very best
intrinsic a-Si:H layers have diffusion lengths, which are well below 1 µm. Therefore,
diffusion is not a suitable transport mechanism for collecting the photo-generated
carriers within an a-Si:H solar cell. Sufficient collection only becomes possible with
the help of an electric field E, i.e. by using drift as transport mechanism. To obtain a
4 Doped (a-Si:H) layers have even poorer quality.