Abstract: Minority carrier bulk lifetime maps are accomplished using in-situ .mu.-PCD measurement techniques on a non-oxidized Si specimen of either polarity. Surface passivation of the specimen is accomplished chemically, preferably using a solution of iodine in ethanol with a concentration in the range of about 0.02 mol.multidot.dm.sup.-3 to about 0.2 mol.multidot.dm.sup.-3. For n-type specimens, a solution of concentrated alkaline such as ammonia, sodium- and potassium-hydroxide is especially effective. For either type specimens, a solution of HF at about 40% m/m is also effective. Surface passivation according to the present invention reduces surface recombination velocities to 10 cm/second or less. The specimen to be measured is placed in a container of passivation solution such that the specimen surfaces are covered with a solution film of about 1 mm or less. The container preferably is transparent to microwave and laser optical energy, and passivation and measurement can occur simultaneously.