Two improved switching circuits for transient electrical short-circuit decay are presented that allow more accurate determination of base-region minority-carrier lifetime and back-surface recombination velocity of silicon p-n junction solar cells and diodes. In one circuit, metal-oxide-semiconductor transistors replace the bipolar switching circuit used in the original implementation of the method as described by T.W. Jung, et al. (ibid., vol.ED-31, p.588, 1984). In the other circuit, a pulse generator directly excites the device under study. Comparison of the two circuits by illustrative measurements shows that, in comparison to the original implementation of the method, these versions allow measurement of shorter effective lifetimes, such as those characteristic of low-resistivity (about 0.1 Omega -cm) silicon solar cells.< >