STUDY OF APPLICABILITY OF AC PHOTOVOLTAIC METHOD AND PHOTOCONDUCTIVE DECAY METHOD USING MICROWAVES AS NONCONTACT METHODS FOR BULK LIFETIME MEASUREMENT

The applicability of the ac photovoltaic method and photoconductive de cay method using microwaves (mu-PCD method) as bulk lifetime measureme nt methods were studied. Lifetimes measured by these two methods were compared with bulk lifetimes measured by the photoconductive decay met hod standardized by ASTM:F28-75. Lifetimes measured by the ac photovol taic method were in good agreement with the bulk lifetimes of less tha n 3 ms for both n-type and p-type samples. However, lifetimes measured by the mu-PCD method were significantly lower than the bulk lifetimes . It is concluded that the ac photovoltaic method is a reliable noncon tact method for the bulk lifetime measurement of the samples with bulk lifetimes less than 3 ms.