Screen-printing SiGe layer on Si substrate for III-V solar cell application.

A silicon-germanium (SiGe) liquid phase epitaxial growth film was formed on silicon (Si) substrate using screen printing and an aluminum (Al) germanium (Ge) mixed paste. AlGe paste is screen-printing on Si (111) substrate and then annealed in an infrared (IR) furnace with different gas ambient. The formed SiGe layer has been cross-sectionally observed by scanning electron microscope (SEM), transmission electron microscope (TEM) and elementally analyzed by energy dispersive X-ray spectrometry (EDX). It was observed that the SiGe layer formed by this method was epitaxially grown crystalline SiGe and had few threading dislocations. The process of this experiment resulted in the formation of 8 µm SiGe, and the Ge concentration increased from 30% toward the substrate surface to around 90% near the surface, demonstrating its potential as on-Si substrate for III-V solar cell epitaxy. [ABSTRACT FROM AUTHOR]