Surface and bulk passivation of multicrystalline silicon solar cells by ...

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Figure 1.4 The I-V characteristic of a solar cell with maximum power point [17].
In solar cell applications, this characteristic is usually drawn inverted about the
voltage axis, as shown above. The cell generates no power in short-circuit (when
current is Ι,) or open-circuit (when cell generates voltage Vo,). The cell delivers
maximum power, Ρ max, when Operating at a point on the characteristic at which the
product IV is maximum. Js^ Von, and fill factor FF are related by:
J, Von, and fill factor FF are the three key parameters characterizing solar cell
performance. The maximum limit for JSis given by the photogenerated current
density, J 1 1. V0, cannot exceed Egap/q (q is the charge of an electron) and is, in
general, quite a bit lower due to recombination.
For open-circuit conditions, all photogenerated carriers recombine within the
solar cell. Thus, if recombination can be minimized, Voc can more closely approach
the limit (Egap/g). However, from thermodynamic considerations of the balance