Surface photovoltage (SPV) method for the characterization of multicrystalline silicon material for photovoltaic applications has been investigated, in view of its application as in-line characterization tool in photovoltaic industry. Minority carrier diffusion lengths have been measured by SPV on as-grown multicrystalline Si wafers as well as on emitter diffused multicrystalline Si wafers, showing the capability and the flexibility of the method. The usual assumptions for SPV data analyses have been critically discussed. The SPV values of diffusion length have been related with material characteristics and process control. (C) 2002 Elsevier Science B.V. All rights reserved.