COMPARISON OF DIFFERENT SIMPLE FABRICATION PROCESSES FOR HIGH EFFICIENCY SILICON SOLAR CELLS

M.J.L. TAMASI; J. PLA; C.G. BOLZI; M.G. MARTÍNEZ BOGADO; G.L. VENIER; J.C. DURÁN

Viena, Austria

Conferencia; 2nd World Conference and Exhibition on Photovoltaic Solar Energy Conversion; 1998

Two simple fabrication processes for high efficiency crystalline silicon solar cells, proposed in the literature during the last years, are analysed and compared, essentially in what concerns to the diffusion and drive-in steps. Both use POCl3 liquid source for n doping. Alternative processes are also proposed. The influence of the concentration of POCl3 during the predeposition step on the repeatability of the wafers sheet resistance is evaluated. The thickness of the passivating SiO2 layers grown during the diffusion process for different techniques are also presented. Techniques for produce devices with a thin SiO2 film, appropriate as passivation interface but not interfering with a more sophisticated antireflecting coating, are proposed and analysed. Several n+pp+ silicon solar cells were fabricated on Czochralski p-type wafers using the processes previuosly analysed. Characterisation of the final devices is given.