A thin silicon solar cell having a high quality spin-on dielectric layer is described. Specifically, the solar cell may be fabricated from a crystalline silicon wafer having a thickness from 50 to 500 micrometers. A first dielectric layer is applied to the rear surface of the silicon wafer using a spin-on process. A high temperature furnace operation provides simultaneous emitter diffusion and front and rear surface passivation. During this high temperature operation, the front emitter is formed, the rear spin-on dielectric layer is cured, and the front dielectric layer is thermally grown. Barrier layers are formed on the dielectric layers. Openings are made in the barrier layers. Contacts are formed in the openings and on the back surface barrier layer.
 The U.S. Government has a paid-up nonexclusive, nontransferable, worldwide license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of contract No. DE-FC36-07GO17023 awarded by the U.S. Department of Energy.