High-resolution optical methods for characterization of polycrystalline GaAs thin films

Two optical characterization techniques capable of high lateral spatial resolution are applied to the investigation of polycrystalline GaAs. The first technique yields the minority-carrier diffusion length and is based on a measurement of the change in photocurrent collected at a semitransparent Schottky barrier as reverse bias is varied. The second involves a measurement of photo-luminescence intensity. The methods yield information on grain boundaries and granular properties, are compatible with conducting substrates, nondestructive, and have a potential for rapid data acquisition.