Measurement of diffusion length, lifetime, and surface recombination velocity in thin semiconductor layers

A small-signal admittance method is developed for the determination of two important parameters affecting the performance of several semiconductor devices with thin layers such as I²L and MOS transistors, OCI-HLE, BSF and TJ solar cells. These parameters, the minority-carrier diffusion length (or the minority-carrier lifetime) and the surface recombination velocity, are found using a combination of low-frequency and high-frequency admittance measurements. The theoretical base of the method and experimental results showing its application and usefulness are presented.