In this article, an expression for the surface passivation has been derived in terms of the surface recombination velocity and the field-effect exponential. The analytical solutions provide a comprehensive understanding of the injection dependency of minority charge carrier lifetime as measured by photoconductance decay. The model has been utilized to analyze the field-effect passivation of silicon exerted by the fixed dielectric charge in an overlying dielectric film. Possible limitations and restrictions of the technique are also addressed. © 2014 AIP Publishing LLC.