The book addresses the problem ofpassivation at the surface of crystalline silicon solar cells. Morespecifically, it reports on a high-throughput, industrially compatibledeposition method for Al2O3, enabling its application to commercial solar cells.One of the main focus is on the analysis of the physics of Al2O3 as apassivating dielectric for silicon surfaces. This is accomplished through a comprehensivestudy, which moves from the particular, the case of aluminium oxide on silicon,to the general, the physics of surface recombination, and is able to connecttheory with practice, highlighting relevant commercial applications.