Extension of the open-circuit voltage decay technique to include plasma-induced bandgap narrowing

An expression for the open-circuit voltage decay is derived to include the effects of plasma-induced bandgap narrowing, as well as the effects of Fermi-Dirac statistics. As a result, the range of validity of the open-circuit voltage decay technique is extended to highly injected carrier densities in silicon in excess of 10¹⁷ cm^-3. The theory, when applied to data from the point-contact concentrator cell, in which highly injected carrier densities have been reported, provides a result consistent with recently determined values for the Auger coefficient and the intrinsic carrier concentration. In the course of the modeling, useful analytical expressions for both experimental and theoretical determinations of the bandgap narrowing have also been found