Effect of pn coupling on open-circuit photovoltage decay in a silicon pn junction solar cell

Abstract

A theory of open-circuit photovoltage decay in a pn junction solar cell is presented which accounts for the pn coupling, i.e. the coupling between the diffused layer and the base of the solar cell. The results have been analysed in some detail which show how the voltage decay is influenced by the various parameters of the diffused layer. It is found that the decay is sensitive to pn coupling in the initial stages, particularly in those solar cells in which a heavy doping of the diffused layer may have caused sufficient band-gap narrowing. A measurement of the voltage decay in the initial stages can therefore yield the parameters of the diffused layer in a solar cell.

Open-circuit voltage decay transient in dislocation-engineered Si p–n junction

“…To our knowledge this is the first study of the open-circuit voltage decay transient in DE Si and we demonstrated the possibility of exponential decay of V oc (t). However, the results in figure 2 are different from those observed in some dislocation-free solar cells with a linear decrease in V oc (t) after the illumination is switched off [21][22][23][24]:…”

“…It is found [11][12][13][14][15][16][17] that V oc can decay according to the exponential function. However, in some dislocation-free solar cells V oc is found [21][22][23][24] to decrease linearly with time after the illumination is switched off.…”