Dick you say I m just saying that that MOS cap analysis is not compatible with what happens in a transistor when the source and drain are biased to remove those electrons as fast as they can be provided You can still get an equilibrium of sorts but the generation current will all be coming out the S D terminals and the amount of inversion charge will be negligible compared to the MOS cap equilibrium I don t want to offend you Dick but this remark is rubbish The inversion layer is determined as pointed out above and is not based upon dynamics in which the SRH generation tries to compete with the drain and source sucking carriers out of the channel Please read over the texts I have suggested to you