Title :
Bulk passivation in silicon ribbons: a lifetime study for an enhanced high efficiency process
Author :
Kaes, Martin ; Hahn, Giso ; Metz, Annekatrin
Author_Institution :
Dept. of Phys., Konstanz Univ., Germany
Abstract :
The effectiveness of hydrogenation either by deposition plus firing of a PECVD SiN layer in a conventional belt furnace or by remote H-plasma was compared quantitatively using spatially resolved lifetime measurements for EFG and string ribbon. Additionally the effect of a preceding phosphorous gettering on the hydrogenation and the presence of a screen printed rear side aluminum during firing was analyzed. Wafer areas with the presence of a rear side aluminum show additional lifetime improvements for both hydrogenation methods probably due to a gettering effect. With preceding P-gettering hydrogenation by SiN deposition plus firing is superior to remote H-plasma. A synergetic effect of a rear side aluminum as described elsewhere is not obtained. First high efficiency EFG solar cells using a PECVD SiN fired in a conventional belt furnace were processed with efficiencies in the 17-18% range.
Keywords :
crystal growth from melt; diffusion; elemental semiconductors; firing (materials); getters; hydrogenation; life testing; minority carriers; passivation; phosphorus; plasma CVD; refractive index; silicon; solar cells; EFG solar cells; PECVD; Si:P; SiN; aluminum; belt furnace; hydrogenation; passivation; phosphorous gettering; remote H-plasma; silicon ribbons; spatially resolved lifetime measurements; synergetic effect; Aluminum; Belts; Charge carrier lifetime; Crystallization; Furnaces; Gettering; Passivation; Silicon compounds; Spatial resolution; Strontium;
Conference_Titel :
Photovoltaic Specialists Conference, 2005. Conference Record of the Thirty-first IEEE
Print_ISBN :
0-7803-8707-4
DOI :
10.1109/PVSC.2005.1488282
