On the choice of the test structure for the electrical characterization of dielectrics for silicon solar cells

Abstract

Surface passivation of Si solar cells is typically achieved by deposition of a dielectric layer. Via the investigation of Al(2)O(3) passivation layers, we show that care must be taken when performing capacitance voltage (C-V) measurements is order to obtain results that are meaningful at solar cell level. The passivation properties of a dielectric are not only affected by post-deposition treatments but also by the presence and the nature of a metal covering the dielectric. Consequently, this Letter emphasizes how important it is to perform C-V measurements on a device structure that resembles as closely as possible that of the finished solar cell, using the same metal, deposition technique and thermal budget. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim