20.10.2018 Views

knjiga solarna energija dobra

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

A REVIEW OF CURRENT THIN-FILM SI CELLS 313<br />

Photon flux density × 10 17<br />

[photon/cm 2 /s/µm]<br />

Photon flux density × 10 17<br />

[photon/cm 2 /s/µm]<br />

0.464<br />

0.417<br />

0.371<br />

0.324<br />

0.278<br />

0.231<br />

0.185<br />

0.138<br />

0.092<br />

0.045<br />

0.000<br />

00.0 30.3 60.6 90.9 121.2 151.5<br />

Depth<br />

[µm]<br />

1.163<br />

1.046<br />

0.930<br />

0.813<br />

0.697<br />

0.580<br />

0.464<br />

0.348<br />

0.231<br />

0.115<br />

0.000<br />

0.00 1.06 2.12 3.18 4.24 5.30<br />

Depth<br />

[µm]<br />

(b)<br />

(a)<br />

181.8 212.1 242.4 272.7 303.0<br />

6.36 7.42 8.48 9.54 10.60<br />

Figure 8.5 Calculated photon flux absorbed within the thickness of a (a) 300-µm wafer; and<br />

(b) 10-µm thin film. Both structures have double-sided texture and an Al back-reflector<br />

times higher at each interface; implying that carrier generation at the interfaces of the<br />

thinner cell is about three times higher. Consequently, for the same surface-recombination<br />

velocity, the carrier recombination for the thinner cell will be 3 times higher. Therefore,<br />

it is imperative that an efficient TF-Si cell design will minimize contributions from all<br />

components of surface-related recombination.<br />

It is important to recognize that there can be several contributions to the surface<br />

recombination in a solar cell (in addition to that from the cell-air interface). These

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!