BLUE EMISSION IN TETRAETHOXYSILANE AND SILICA-GELS

Tetraethoxysilane (TEOS), a well-known SiO2 precursor, and silica gels prepared with it were characterized in terms of their optical propert ies in the 200-800 nm range. A distinctive blue emission is detected n ot only in the gels but also in the TEOS itself. Further heat treatmen ts of the gels allowed the evolution of the blue signal to be followed ; the origin of this emission is discussed in terms of the structure o f the material.