INFLUENCE OF DISLOCATIONS ON DARK CURRENT OF MULTICRYSTALLINE SILICON N+ P JUNCTION

A detailed characterization of the dark current in large grained polycristalline silicon cells is given. This current is greatly influenced by the presence of dislocations. A new model for the shunt current transmitted by these defects is given. It is found that this current is proportional to exp(qV/2 kT). The comparison between the three essential components of the dark current (diffusion, recombination and shunt component) indicates that the shunt component is the dominant one at low applied voltage (V < 300 mV). Even at higher voltage (V > 300 mV) the shunt component is comparable to the diffusion one when the dislocation density is greater than 10(5) cm-2. The computed results are in agreement with experimental ones.