ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
We measure a low effective back-surface recombination velocity S≈1000 cm/s on boron-implanted back-surface field (BSF) silicon solar cells with a p-base resistivity of 0.3 Ω cm. For cells of this low resistivity, this velocity is much lower than values obtained with the conventional Al-alloying technique. Our data indicate that the low surface recombination velocity results from a low value of minority electron diffusivity D≈0.45 cm2/s peculiar to these highly doped implanted regions at the back of the solar cells. The effect of a thermal anneal at 950 °C, prior to emitter fabrication, on the solar cell parameters was also investigated. The short-circuit current density, minority-carrier diffusion length, and back-surface recombination velocity, improved with a 1- and 2-h anneal of the BSF cells, and either degraded or remained unchanged on ohmic back contact cells. The decrease in S is due to widening of the BSF region during anneal, deduced from spreading resistance measurements.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.340123
Permalink