Abstract
A method is presented whereby short minority carrier diffusion lengths in semiconductors may be determined by measuring the variation of surface photovoltage as a function of optical absorption coefficient. The method does not depend upon the specific form of the relationship between the surface photovoltage and the density of the excess minority carriers injected at the bulk edge of the surface space charge region. Only capacitive contacts to the sample are needed for the measurement. The method has been used to determine the minority carrier diffusion length in both n and p type gallium arsenide.