A Study on Minority Carrier Diffusion Length of Semiconductor with Constant Measure of Surface Photovoltage

To evaluate the quality of silicon, based on the integrity of materials, a system using surface photovoltage to measure the minority carrier diffusion length of semiconductor. The system can be used to obtain the surface photovoltage by the method of chopper, monochromator and Lock-in amplifier. We get the minority carrier diffusion length of semiconductor by the use of the relationship between the surface photovoltage and the optical absorption coefficient of materials. The measuring principle of the system and the realizing methods for all models are explained in detail. The results showed that a constant measure of surface photovoltage method for measuring the semiconductor minority carrier diffusion length to achieve the intended results.