Transient and quasi-steady-state photoconductance decay measurements of lifetime are the limiting cases of the general equation given as .
In the case of transient measurements, the pulse of light is only to excite the carriers and is off during the actual measurement so that G(t) = 0. For the QSS measurements, it is assumed that the light is varying very slowly so that d(Δn)/dt = 0.
The generalized form of the equation is useful when the flash and wafer have similar time constants.
- 1. , “Generalized analysis of quasi-steady-state and quasi-transient measurements of carrier lifetimes in semiconductors”, Journal of Applied Physics, vol. 86, pp. 6218-6221, 1999.